UC Master Gardeners, Santa Clara County, CA
University of California
UC Master Gardeners, Santa Clara County, CA

Fruits & Nuts

Garden Help > Monthly Tips

Here's a collection of tips related to growing fruits and nuts.

 

Fruit & Nut Tips

Almond and Walnut Harvest

Almonds are harvested when the shell is cracked and brown. Freeze nuts for 1-2 weeks to kill resident worms, store nuts in plastic bags to prevent re-infestation, and spray the tree with fixed copper during or after leaf fall but before rains start to reduce damage from shot hole fungus.

Walnuts are fully mature when green hull begins to break away from the shell. Harvest by poling or shaking the tree. Remove the green hulls, then freeze nuts in the shell to kill any resident worms. Store in plastic.

Apple and Pear Harvest

The harvest for apples, and some varieties of pears (Bosc, Comice, Winter Nellis, and some Asian Pears), is likely coming to a close. When harvest is finished, irrigate and fertilize the trees as you have been. Clean up fallen leaves and fruit and discard to prevent apple scab and coddling moth.

Avocados, Brown Spot

The brown patch that looks like a turtle's back is called Carapace Spot. It is corky and usually cracked into angular divisions. It is caused by rubbing or brushing of tender young fruit on leaves or stems in the wind, but the fruit is usually undamaged under the spot. Just cut out the spot. More pictures of avocado problems can be found on UC Pest Note On Causes of Avocado Fruit Damage.

Bare Root Plants

Bare root plants are sold without any soil clinging to the roots making them easier and less expensive to transport; they'll do just fine in the garden as long as you don't let them dry out before planting. Because you can see the roots and can control how they're placed in the soil, it helps reduce the chances for root girdling problems later. Buy and plant early in the month while roots are still fresh.

The bare roots should be soaked from an hour to overnight (large plants) in a bucket of water before planting. Trim roots of broken, dead or spongy bits and carefully pull the roots apart. Dig a hole that is fairly shallow and wide. Spread the roots out sideways and have the crown of the plant several inches above the soil level. This is necessary as the plant will settle down over time. Water in well but wait to fertilize until you see new shoots growing. Be sure to water regularly if the rains are sparse. Staking may not be necessary.

Trees aren't the only plants that are sold bare root. You can also plant bare root asparagus, artichokes, rhubarb, berries, kiwifruit, horseradish, rhubarb, grapes, roses, strawberries, and iris in January.

Bare-Root Fruit and Nut Trees, Berries and Grapes

March or April is an excellent time to add bare root fruit and nut trees, grape vines, and bramble fruits to the landscape. These perennial edibles can provide decades of food production with a minimal investment of time and money. For more detailed information on specific varieties, take a look at the UC Backyard Orchard website.

Bitter Pit (Brown Spots) on Apples

Bitter pit is a physiological disorder that affects many varieties of apples. The condition develops after fruit has been picked. It is caused by low levels of calcium in fruit tissues which leads to small brown, sunken lesions that become dark and corky. Highly susceptible cultivars include Red Delicious, Granny Smith, Golden Delicious, Jonathan and Gravenstein. The UC Bitter Pit Pest Note recommends cultural practices for control.

For even more information, the UC Postharvest Technology Center website has grower information, including using calcium sprays starting in June.

Blueberries

Depending on the variety, you may be harvesting blueberries from your garden right now. Blueberries in stores often come from cooler climates like Oregon and Maine, yet there are several varieties of blueberries that do well in our warmer climate with a little extra care. They all need regular water and well-draining soil with a lower pH (more acidic) than our local native soil. Adding elemental sulfur is a good way to acidify the soil. Harvest blueberries on almost a daily basis, especially if you want to beat the birds and squirrels to the ripe berries. The blueberries are ready to eat when they are uniformly blue/purple, even on the bottom. They should come off easily with a slight tug. Annual post-harvest pruning will stimulate new growth and increase yield. Details are available in a video presentation by a local UC Master Gardener.

Brown Marmorated Stink Bug

Native to Eastern Asia, this pest was introduced to the United States in the 1990s and has been established in Santa Clara County. Some features to distinguish these bugs from other stink bugs are white stripes on the antennae, a blunt head shape, and smooth shoulder margins.

They feed and reproduce on a variety of plants and are particularly damaging to fruit. You can cut cosmetic damage off fruit and still eat the rest of the fruit. To keep out stink bugs, cover vegetable plants with row covers. You can pick the bugs off plants and squish them or knock them off into soapy water. They are attracted to light and can get into homes where if vacuumed up, they can stink up your vacuum bag.

 

Brown Rot on Apricot and Peaches

Brown rot apricot fruit mummy. Photo by WW. Coates, UC Cooperative Extension.If your apricots or peaches had brown flesh last year, especially in the part surrounding the pit, they were probably infected with brown rot. It's a common fungal disease of stone fruit. You can spray with a copper spray at pink bud stage. A more important means of control is to remove affected fruit as soon as you notice it. The UC Pest Note on Brown Rot has more information.

Citrus Bud Mite - Leave It Alone

Lemon affected by citrus bud miteHave you ever seen weirdly shaped lemons or oranges that appear to have 'fingers'? This condition is caused by the Citrus Bud Mite. 

It attacks newly forming flowers and fruits. The mite is only visible with a magnifying glass and has a elongated yellow body with four legs that appear to come out of its head. The mites feed inside the buds, killing them or causing a rosette-like growth of the subsequent foliage and distortion of flowers and fruit. The problem is usually limited to just a few fruit on the tree.

Previously recommended oil sprays have not been proved effective. This is one of those pests that is best left alone. The oddly-shaped fruit is edible.

For more information see UC Pest Note on Citrus Bud Mite.

Citrus Fertilizing

Honey bee on citrus blossom
Honey bee on citrus blossom
In California, most soils contain adequate nutrients for citrus growth, except nitrogen. Nitrogen is the primary nutrient required by the trees, and there are commercial fertilizers balanced specifically for citrus. One-year-old trees will need 1/10 of a pound of nitrogen, while mature trees need approximately 1-1/2 pounds. These amounts should be divided into two to three applications.

Blood meal without all the fillers is an excellent source of nitrogen, or you can purchase a balanced product that contains zinc. Spread the fertilizer evenly over the entire root area and water in.

For more information, refer to the UC Pest Note on Fertilizing Citrus, and Questions and Answers to Citrus Management from the UC Davis Home Orchard website.

Citrus Fruit Damage

Your oranges are ready to pick when they turn a nice bright orange. The ones on the sunny side of the tree generally ripen first. If you don't get to them first, there are critters that will let you know when they are ripe. Snails leave little holes in the outside peel, rats hollow out the fruit, and squirrels carry them off, often leaving partly eaten fruit on a nearby fence. UC Davis offers a detailed table to help identify citrus damage from insects and other pests.

Citrus Leaf Drop & Yellowing

Leaf drop from citrus trees is normal. Washington Navel oranges may lose over 3,000 leaves a day during peak leaf drop in the spring. Valencia oranges may lose about 1500 a day. Problems that can cause excessive leaf drop beyond these numbers are lack of water and a heavy infestation of spider mites. The tree's leaves will have brown spots if affected by the mites. You can wash them off with a strong water spray. Bud and small fruit drop is also normal. For further information see UC Pest Note on Diseases and Disorders of Citrus Leaves and Twigs.

Citrus Pruning and Care

Once the threat of frost is past (typically March 15), it's a good time to cut back branches that touch the ground, fences, or other structures. Thin the tree to let more air into the middle. Trim out crossing branches and anything that looks dead.

Pruning is not needed for fruit productivity yet may be desired for size management. Pruning will also help control scale and aphid infestations. If you see ants in the tree, use a sticky goo (such as Tanglefoot) on the trunk to keep them out of the tree. Be sure to apply the goo on top of tape rather than directly on the trunk. The ants 'protect' the scale and aphids. If you see scale (bumps on bark), thoroughly spray with horticultural oil to suffocate them.

Yellowing of leaves is normal this time of year as the iron that keeps the leaves green is chemically unavailable because the soil is too cold. When the soil warms up (over 60° F), check for yellowing. You may not need to apply a nitrogen fertilizer if the new leaves are green.

Refer to the UC Home Orchard web site for more Citrus Care information.

Citrus Quarantine Warning

Quarantine on citrus fruits, leaves, and trees; also Indian curry leaves: Most of Santa Clara County is under quarantine for citrus due to the Asian citrus psyllid and huanglongbing disease. Check the Santa Clara County Quarantine Map to see if you're affected and review our Asian citrus psyllid page for what can and can't be moved across quarantine boundaries.

Citrus Sooty Leaves

Sooty mold on citrus may be a byproduct of sucking insects such as aphid, mealy bug, soft scale or whitefly. Ants will protect these pests against predators in exchange for the honeydew that the pests produce. The sooty mold grows on the honeydew. Try washing off the sucking insects with a strong water stream. The next step is control of the ants. Ants may be managed by applying a sticky compound around the trunk and trimming limbs touching buildings or other access points. Baits at the base of the tree also help. For more information about specific controls, see the UC Pest Note on Sooty Mold.

Clean Up Fallen Fruit

Pick up fallen fruit daily to prevent attracting critters or diseases. If your fruit is being eaten at night then rats are the likely culprit, if it's during the day it may be squirrels. Holes, rather than bites, are made by birds. In addition to harvesting regularly, ripening fruit can be protected with a netting fine enough to exclude birds and small animals

Codling Moth

"Worms" in your apples are actually the larval form of the codling moth. Codling moth larvae can cause a great deal of damage to apples, pears, plums and walnuts by penetrating the fruit and boring into the core.

Trees should be monitored every week for signs of infestation. Infested fruit should be removed and discarded, to break the coddling moth life cycle. Sanitation is an important non-chemical step in controlling this pest. Make sure to pick up fallen fruit promptly, and pick apples with holes that are still on the tree. This will keep future populations down.

Pheromone traps can be hung in isolated trees. But if you have just one apple tree don't bother. You will just attract codling moths to your tree.

Fruit can be bagged for protection, but this is a very labor intensive method. Heavy infestations may require the use of pesticides on the moths, before fruit is affected. For more information, refer to the UC Pest Note on Codling Moths.

Consider Dehydrating Some Of Your Harvest

If you have more fruit than you know what to do with, dehydration can be an excellent way to preserve it. Apricots, apples, pears, figs, and tomatoes are all great candidates for drying. While making jams, jellies, cobblers, and pies is one way to use up an abundant harvest, they add fat and sugar to our diet, dried fruit can be a healthy alternative! Onions and garlic can also be dehydrated to last indefinitely.

Also see the publication on Dehydrating Basics by the UCCE Master Food Preservers of Amador/Calaveras Counties.

Control Insect Pests with Horticultural Oil

Spray apple, pear, peach and nectarine, apricot trees with horticultural oil during the dormant period to control scale, and aphid and mite eggs. For more information on using horticultural oil to control pests consult:
- UC Pest Note on Scales
UC Pest Note on Aphids
- UC Pest Note on Spider Mites

 

Cottony Cushion Scale

Cottony cushion scale on apple tree, by Laura Monczynski
Cottony cushion scale on apple tree, by Laura Monczynski
Scale insects populate the stems or branches of plants and suck out the nutrients. Some are soft and some are armored during part of the life cycle. Cottony cushion scale is a soft variety that is often seen on apple trees. The crawlers are reddish and the females develop elongated white egg sacs on their backs, but it is most likely the molting skins that look like cotton that will alert you to their presence. Small infestations can sometimes be wiped off with gloved fingers. Natural predators may also move in to take care of the problem. There are beetles and parasitic flies that can provide good control. Keeping ants out of the tree will also help because ants will protect the pests in order to be able to eat their sugary exudate. 

More information: Cottony Cushion Scale Pest Note

Don't Fertilize Now

Except for cool-season vegetables and lawns, most plants will be dormant or growing very slowly during this time of year. Fertilizing is most beneficial when plants are actively growing or developing fruit or flowers. Even citrus which ripens during the winter is best fertilized for the last time of the year before October 1. Some California native plants are active in the winter, but they evolved in our native soil and generally do not need supplemental fertilization. Fertilizing plants now will create tender new growth right before the risk of frost. Some nutrients cannot be taken up efficiently by plants during cold weather. The excess can leach into the groundwater or run off and reach the bay. Ultimately, using unneeded additives is a waste of resources and money.
 
More Information: Dormant Season
 

Dormancy and Chill Hours

The positive side of cold weather is that fruit trees native to colder climates, such as cherries and blueberries, may get the chill hours they need to produce good fruit. Going dormant saves energy which can then go into fruit development. No need to protect them on cold nights. Knowing the native habitat of your plants will guide you in caring for them. Mimicking the success of nature leads to greater success in your own garden.

Learn more about chill hours on the UC Fruit & Nut Information website. UC has historical chill hours available for many locations in California, however, Gilroy is the only location located in Santa Clara County. For county locations closer to the Bay, the Union City station may be more applicable (or view a map of all station locations).

Dormant Oil Spraying

San Jose Scale
San Jose Scale
Deciduous fruit trees lose their leaves seasonally, usually in the autumn. They enter a period of dormancy when they are not actively growing and there is little activity within the plant. This is the time to apply dormant oil sprays to smother soft-bodied insects such as scale, aphids, and mites. First, do any needed pruning so that you will not be spraying branches that will soon be removed. Then inspect for pests that are overwintering on the trees, or remember pest and disease problems you noticed during the growing season. Although dormant oils may count as organic, it is still best to use them only if pest problems have been observed. 
 
Mix the horticultural oil in a sprayer and apply it according to directions on the packaging. Never use more than what is prescribed. Make sure to complete the spraying before the trees start to bud and blossom so as not to damage developing flowers and fruit.
 
 

Eugenia Psyllid

This psyllid has been a real problem in California. New leaves on the infected Eugenia look very much like peach leaf curl. The leaves also may become discolored. Thanks to the diligent work of the entomology researchers in biological insect control at UC Berkeley, a parasitic wasp called Tamarixia was released in Santa Clara County in 1993. The wasp is known to go as far as 45 miles and is found throughout the county. It is essential that no insecticide be used on Eugenia species. The Tamarixia wasp cannot do its job if it's poisoned. For more information see the UC Pest Note on Psyllids.

Eutypa Dieback on Apricot Trees and Cherry Trees

The sudden dieback of individual branches during mid to late summer can lead to dry brown leaves that may remain on the branches until the following winter. This is due to a fungal parasite caused by airborne spores that enter fresh pruning wounds. Cankers develop around an infected wound and eventually kill the branch. Death can take months or even years. The danger of spreading is highest in the fall during early rains and again in the spring. Prune apricot trees and cherry trees in July or August before fall rains begin. Apricot and cherry trees should be pruned at least 6 weeks before the first rain falls. If it rains before the pruning cuts heal, the tree is more susceptible to infection by Eutypa spores that cause dieback. See UC Pest Note on Eutypa Dieback

Fall Garden Cleanup

It’s an excellent idea to keep the garden clean at all times and to remove dead or dying plants or diseased material. Yet there may be bigger seasonal cleanups when taking out plants that have finished producing or that need to be removed to make room for new plants. Trim woody or overgrown perennials. You should remove plant debris that allows insects and diseases to overwinter and then reproduce. In particular, always pick up fruit promptly from the ground so as not to invite critters or to allow diseases to proliferate. You can either leave healthy fallen leaves in place to form a mulch or you can rake them up. Monitor the health of your plants while you're out cleaning up. 
 
 

Fertilizing Fruit Trees

As fruit starts to develop, trees and vines use nutrients to help with this energy-intensive task. This is a good time to plan a strategy for fertilizing your trees.

In the first year, a very light application of nitrogen (N) is desirable for most soils. Do not make first year applications before six to eight inches of new growth occurs. Split applications are safest, one or two months apart, so one application might be made this month.

After the first year: research indicates that summer fertilizer applications (August to mid-September) are more efficient than late winter (traditional) applications.

Fully mature fruit trees may not need fertilizing. Read more at UC Home Orchard Fertilization page.

Free the Trees

As your young trees grow bigger and stronger, remove supporting stakes or loosen the straps as early as possible. Some movement of the tree is important to make it healthier in the long run. If the tree is able to stand on its own, it will develop a thicker trunk with a taper at the bottom.

Fruit Tree Dormant Care

If you've had major pest infestations on your fruit trees this year, now is a good time to use dormant oil sprays. These are used to reduce overwintering populations of insects. They work by smothering soft-bodied insects and eggs when applied at the proper times in the life cycles of the pests. See our Fruit Tree and Vine Care Calendar for more information.

Fruit Tree Grafting

When pruning dormant fruit trees, you may want to save cuttings (scions) for later grafting onto other fruit trees.  Grafting is a technique that allows you to have multiple varieties of compatible fruit on one tree and is a great space saver. Fruit trees can have new varieties grafted to them when they are dormant in January and February.

Scions are available in January at the California Rare Fruit Growers (CRFG) scion exchange. Their January event also includes training classes. Check the CRFG - Santa Clara blog for the date.

More information on grafting can be found at:

- Grafting and Budding on the UC Home Orchard website
- Grafting Dormant Deciduous Fruit Scions at the California Rare Fruit Growers website
Budding and Grafting Demystified from the UCCE web site

Fruit Tree Harvest

If you have fruit trees that are ready to pick and more fruit than your family can use, please contact Village Harvest. Village Harvest is a non-profit volunteer organization in the greater San Francisco Bay Area that harvests fruit from backyards and small orchards, then passes it along to local food agencies to feed the hungry. They also provide education on fruit tree care, harvesting, and food preservation.

Garden Sanitation

Fruit mummy with brown rot sporulation, by William W. Coates, UC
Fruit mummy with brown rot sporulation, by William W. Coates, UC
Keeping the garden clean can help keep it healthy. Remove spent blossoms, fruit, and other plant parts as your plants finish producing. Dead and decaying plant parts can attract pests and give them safe places to breed. Insect pests damage plants directly by eating material or sucking out juices and nutrients, and they also spread diseases between plants as they move around. Weeds compete with desirable plants for water and nutrients and even sunlight, so remove them promptly. Older leaves of some plants, like squash vines, may naturally turn yellow and die. Removing them early allows the plants’ energy to go into the actively growing parts. Pick up fallen fruit that can attract rodents and can also return disease pathogens to the soil and plant. It’s particularly important to remove dried-up fruit “mummies” so that the fungal spores don’t spread. Prune dying tree branches before they can fall and do damage. Some flowering plants will produce more flowers if you remove spent blooms, a process called deadheading. You can leave healthy fallen leaves in place to form a mulch and decompose naturally, or you can rake them up and add them to the compost pile with other disease-free plant material. Do not compost diseased material.

 

Gray Mold (Botrytis)

Botrytis is gray or brownish fuzzy mold that can attack a wide variety of plants. It likes flower petals, ripening fruits and vegetables, as well as leaves and stems. The spores are spread through the air. It is most severe when there's high humidity and may start forming on decaying matter. According to the UC Pest Note on Botrytis Blight, it is important to remove debris and prunings from the ground. You may even have to pick up flowers daily. Avoid overhead watering.

UC also has information about Gray Mold on Strawberries.

Harvest Kiwis

Pick kiwis in late fall while is still hard like an avocado, softening at room temperature. Watch the vine for signs of ripeness. A few fruit will turn soft or the skin color goes from greenish to full brown. Fruit can be left on the vine after leaves have fallen. You can store in the refrigerator for up to 4 months or at room temperature for about 2 weeks. More details about Kiwifruit Culture is provided by the California Rare Fruit Growers.

How to Tell if Fruits and Vegetables Are Ready to Pick

The UC Davis Postharvest Technology website was designed for commercial growers, but the information on how to tell When Fruits and Vegetables are Mature is handy for home gardeners as well. There's also information about how to Store Fruits and Vegetables for Better Taste.

Limes

Blossom End Rot on a Bearss Lime
Blossom End Rot on a Bearss Lime
Limes are easy to grow in our area and make a pretty addition to the landscape. They don’t take up as much space as some other citrus and can grow well in our native soil with plenty of sun. They need some fertilizing and occasional protection from the cold. Bearss Lime is a popular variety that has fruit ripening now. Other favorites include Mexican Lime, Australian Finger Lime, and a Limequat hybrid. Most limes are yellow when fully ripe and have a higher juice content at this stage; most limes in stores are green because they have a longer post-harvest life or shelf life. A tan, leathery sunken area at the end of the fruit is called blossom end rot in citrus. It can come from insufficient water, preventing calcium from getting all the way to the ends of the fruit (similar to blossom end rot in tomatoes.) You can freeze the fruits whole for year-round margaritas or whatever it is you do with your limes. Freezing weakens the cell walls, which makes it even easier to juice the limes after thawing.

More Information: Growing Citrus Fruits

Melons

By this time the vines have spread out and there are flowers everywhere. A foliar spray of a water-soluble fertilizer will give them a boost now. Keep the water flowing as they are one of the thirstiest plants you can grow. You can set young melons on the top of inverted cans (coffee cans, tuna cans, etc.) to warm them faster and more evenly. Punch a hole in the bottom of the can so water won't puddle and rot the melon. Melons will begin ripening in August. How will you know when it's ripe? The background color behind the netting will turn from green to tan. The stem will slip right off with just a light touch. Last but not least. let your nose tell you if it's ripe. Smell the stem end; it should have a wonderful melon aroma. The color and smell test also works well in the grocery store.

Olive Harvest

Harvest olives grown for the table when fruit is still green. Olives grown for oil can be harvested when the fruit is yellow to reddish-purple and the flesh is still green-yellow. Continue irrigating until first rains. Apply fixed copper to prevent peacock spot before the first major rain, and be sure to wash the fruit before use or wait until after harvest to spray.

Paint Fruit Trees to Prevent Sunburn

After deciduous fruit trees have dropped their leaves, paint tree trunks with white latex paint diluted 1:1 with water to prevent sunburn. Preventing sunburn helps trees resist invasion by shot hole borers, which are tiny beetles that boreholes and lay eggs in the cambium layer of the tree. When the eggs hatch, young larvae feed and excavate tunnel galleries in the wood. For more information about identification and control see UC Pest Note on Shothole Borer.

Peach Leaf Curl Diagnosis

It is too late for chemical control of Peach Leaf Curl in April. If your trees are susceptible, make a note to apply a copper-based spray after this year's leaves drop, and possibly again (for severe problems) in February before the spring bloom. This year’s damaged leaves will eventually fall off and should be disposed of in the trash. The new leaves that are produced are generally fine, but the vigor of the tree may suffer. For more information see the UC Pest Note on Peach Leaf Curl.

Peach Leaf Curl Preventive Care

To prevent peach leaf curl, use resistant peach and nectarine varieties where possible (the Pest Note linked below provides a list.) For non-resistant varieties, treat trees with a fungicide such as a fixed copper spray every year when the trees are dormant (typically December to January). When applying any fungicide, it is essential to cover the trees to the point of runoff or until they are dripping to obtain adequate disease control.

Generally, a single early treatment when the tree is dormant is effective, although in areas of high rainfall or during a particularly wet winter, it might be advisable to apply a second spray late in the dormant season, preferably as flower buds begin to swell but before green leaf tips are first visible.

More Information: Peach Leaf Curl Tips from UC

Persimmon Harvesting

Persimmons - Fuyu
Persimmons - Fuyu
Harvest persimmons. Fuyu persimmons are ready to harvest when they have their full orange color and are still slightly firm to the touch. Hachiya persimmons (with the pointy ends) must be soft and have translucent skin. If you eat an unripe Hachiya variety, you will gain a new understanding of the word “astringent”! Cut them off close to the fruit to avoid damage to the branch from yanking them off. The UC Master Gardeners of Solano County have a nice blog posting about Persimmons.

Picking and preserving oranges

Orange left on tree past its prime, by Laura Monczynski
By now, you may still have a lot of navel oranges on the trees. Valencia oranges are harvested through summer. For the rest, rather than leave it to rot or be eaten by rats, pick what is left soon. Even the ones that don’t fall will not stay good forever. The skin may start to ripple as the fruit inside starts to dry and suffer in quality.  You can store them in the refrigerator for several weeks, but keep an eye out for mold. You can freeze orange sections for later use in orange juice or smoothies, or you can make marmalade or other orange recipes if you have already eaten enough fresh oranges. Picking the remainder allows the tree to put more energy into the current blossoms which will become next year’s fruit. 
 
 

Planting Berries

Berries including blackberries, raspberries, blueberries, and some strawberries can be planted in the fall through early spring. When purchasing blackberries and raspberries, it is best to get plants that are certified disease-free from a nursery. Most berries prefer deep, well-drained, loamy soil with a slightly acidic pH (5.5-6.5). Bare-root plants can be planted in the fall, winter and early spring. Potted green plants can be planted any time they are available in the nursery. A northern sun exposure is best.

Preserving Fruits and Vegetables

Interested in how to preserve fruits and vegetables? UC Food Safety has lots of information including "Safe Handling of Fruits and Vegetables", "Safe Methods of Canning Vegetables", "Chart on Storing Fresh Fruits and Vegetables", and more. Visit their web page UC Home Preservation and Storage Publications for more details.

Protecting Birds and Crops

This is nesting season for many birds, so be sure to check for active nests before pruning trees. Birds are good for natural pest control, as they eat many insects, and they improve your garden’s biodiversity. You can also encourage birds in your yard by providing food and water for them. Just be sure the water stays fresh and clean.

To protect fruit and nut trees from marauding birds, PVC structures covered with netting can save your crop. If netting is placed directly on the tree, birds will still be able to reach much of the fruit. There's more information in the UC Pest Note on Birds on Tree Fruits and Vines.

Protecting Fruit

If you don't eat your fruit the minute before it's ripe, birds or squirrels will. Once you see signs of damage, either pick the fruit, or find a way to protect it. For example using netting or paper bags. Pick up any fallen fruit as so not to attract rats or other less visible pathogens.

Prune Apple Trees

Once your apple tree loses its leaves, it's time to think about pruning. Apple trees produce fruit terminally on spurs located on wood 2 yrs. to 8 yrs. old. Weak and unproductive branches should be thinned out to allow the sunlight into the tree for good spur development. Older spurs can be rejuvenated by cutting back, especially following a light crop year. Tree height is maintained by cutting back upper branches to shorter laterals. Excessive pruning of a bearing tree can negatively affect its vigor and fruit. Consult our Fruit Tree Pruning page for more information.

Prune Apricot and Cherry Trees

There are several ways to squeeze multiple fruits into a small yard. You can graft related fruits onto the same tree, so that one tree might have apricots and plums and peaches or another might have four varieties of apples. You can choose dwarf trees or trees on dwarfing rootstock. You can plant them in larger containers like half wine barrels. You can plant them close together and keep them pruned small. And you can do summer pruning after harvest in addition to dormant pruning in the winter on most trees. Just make sure to do your annual pruning of apricot and cherry trees now so that they have time to heal before it rains again. They are susceptible to a fungus called Eutypa that can kill a tree. If it rains shortly after pruning, the fungus spores can splash up onto the open wounds and infect the tree. Branches will die back first, and the disease can rapidly move into the trunk with fatal results. See Eutypa Dieback on Apricot Trees and Cherry Trees under 3. Pests and diseases. The UC Home Orchard website has more advice on Pruning Apricots.

Prune Blackberries

Little or no pruning is required during the first year after planting. Blackberries should be pruned as soon as the harvest is completed. All wood that has produced the current crop should be removed. The canes should be trellised immediately after pruning. Put up only the larger canes and prune the small ones. Generally, no more than 9 canes should be put up on the trellis. A fan-like arrangement is the best way to trellis the vines. Tipping (removing the end of the canes) forces out the laterals on which fruits will be borne the following season. Consult our Berries page for more information.

Rats

Have you found snail empty shells stashed in out of the way places, hollowed out Navel oranges, Meyer lemons with no skins, tomatoes with bite marks, fruit with holes gnawed in them or grape skins or cherry tomato skins scattered around? This could indicate the presence of rats. The UC IPM Pest Note on Rats provides a wealth of scientific information.

Rats show up when your citrus, tomato or fruit first start to ripen. Rats are agile climbers and usually live and nest in shrubs, trees, and dense ground cover like ivy. Good sanitation is required. Garbage and garden debris should be eliminated. Use tight fitting lids on garbage cans. Thin out dense vegetation to make the habitat less desirable. Mow ivy once a year to the ground. Climbing ivies on fences or buildings should be removed.

Trapping is the safest and easiest method for controlling rats. The simple snap trap is effective. The most important thing about trapping rats is to have lots of patience and keep trying. Wet some oatmeal enough for it to hold together, add dog or cat kibble or bits of lightly cooked bacon mixed in. Tie a walnut to the trigger and add a dab of peanut butter.

Other baits to try are peanut butter and fresh fruit, but try to have something tied to the trigger. Set traps where rats are likely to travel or where you see droppings along fence lines or buildings. Bait the trap but do not set it for several days. Try different baits in multiple traps until you find one the rats like. Put two traps facing each other. After the rats are accustomed to being fed, then set the traps. If the rat springs the trap but doesn't get caught, move the traps to a different place and change to different baits. Rats prefer secluded spots and will be less wary there. Be sure to secure the trap with a wire or nails. Above all be patient and use multiple traps.

Squirrel Control

Squirrels can be particularly annoying because they tend to take one bite out of each piece of fruit, rather than eating the whole thing and leaving the other fruit intact. They are difficult to control, but you can try some of the methods recommended in UC Pest Note on Tree Squirrels and UC Pest Note on Ground Squirrels.

Summer Fruit Tree Pruning

If you want to keep the size of your trees manageable, you can do summer pruning after harvest in addition to the usual dormant pruning.  An advantage of dormant pruning is that it is easy to see the branch structure. An advantage of summer pruning is that it reduces leaf area so the tree produces less energy and doesn't get as large. With apricot and cherry trees it is important to prune them only in the summer when it will be dry for several weeks afterwards.  Apricots and cherries are susceptible to a fungus called Eutypa that can kill a tree. See the August tip "Prune Apricot and Cherry Trees". 
 
More information: Pruning fruit trees
 

Summer fruit tree pruning

Hand pruning by Vera Kark
If you want to keep the size of your trees manageable, you can do summer pruning after harvest in addition to the usual dormant pruning.  An advantage of dormant pruning is that it is easy to see the branch structure. An advantage of summer pruning is that it reduces leaf area so the tree produces less energy and doesn't get as large. With apricot and cherry trees it is important to prune them only in the summer when it will be dry for several weeks afterwards. See the August tip "Prune Apricot and Cherry Trees" on apricot and cherry. 
 
More information: Pruning fruit trees
 

Sunscald on Fruits and Vegetables

Sunscald injury on tomato

Fruits and vegetables can get sunburned in the summer heat. This is more commonly called sunscald and it frequently affects peppers, tomatoes, and persimmons. The leaves shield the produce from the sun, so it helps to make sure the plants have sufficient fertilizer and water for a healthy plant. You can cut out the damaged parts and eat the rest of the fruit.

Thinning Fruits

Don’t worry about small fruit falling off your trees. That’s just nature at work. The trees may put out more blossoms and fruit than they have the energy to grow to maturity. So the trees naturally drop some of the excess fruit. This is called June Drop. Soft fruits like apricots, nectarines, and peaches should not touch each other or they are likely to show some rot. Fruit that grows in clusters like apples should be thinned to 1-2 fruits per cluster. Spacing needs to be balanced with the quality of the fruit, with a focus on keeping the larger fruits that are round in shape and free of blemishes. Thinning fruits starting from April through mid-May when the fruit is less than an inch in diameter so as not to waste the tree’s energy. Shaking the tree can also cause weak fruit to fall. The result will be larger fruits and just as much overall yield by weight. Another way the tree can shed extra fruit is by breaking off a branch that is too heavily laden. Nut trees and citrus do not need to be thinned.
 
More Information: Fruit thinning
 

Water Budgeting

We always need to use water wisely. Sometimes it is necessary to stop and think about your landscape and prioritize water use. Trees are a long-term investment, yet mature trees may have extensive root systems enabling them to find enough water on their own. Fruit trees may need watering approximately monthly during the summer in order to produce good fruit. Vegetables should always be given adequate water in order to fulfill their purpose in the garden; otherwise the little bit of water you used will have been wasted if the garden is not feeding you well. It’s helpful to understand that home-grown vegetables use much less water overall than ones purchased at the store. Established flowering shrubs, especially California natives, tend to need less water than annual flowers and maybe a more water-efficient way to have color and beauty in your garden. Lastly, keep the weeds under control so that they don’t rob water from the plants that you actually want.
 
 

When to Pick Pomegranates?

Split pomegranate, UC photo by Kathy Keatley Garvey
Pomegranates are ripe when the rind changes from a shiny to a matte finish and when tapped make a pinging or metallic sound. In Santa Clara Valley, the fruit generally ripens in October–November or six to seven months after flowering. To harvest, it is better to clip rather than twist the fruit off the stem, which may cause injury to the fruit, stem or both. The fruit will ripen all at the same time and cannot be ripened off the tree. The California Rare Fruit Growers have more information about pomegranates.

Winter Fruit Tree Pruning

Pruning tools: saw, loppers, and hand pruners, by Allen Buchinski
Pruning Tools – Keep them clean and sharp

Remember to keep your pruners and loppers sharp. Good pruners use bypass blades rather than anvil type. Anvils have only one cutting blade and one flat blade which can result in "smashing" the plant material. Sterilize the pruners or loppers between each plant and after cutting off any diseased plant material. Use a 10% bleach solution (1 part bleach, 9 parts water) or disinfectant bathroom cleaner.

What and When to prune

According to UC's Backyard Orchard website, "the optimum time of year to prune fruit trees is the dormant season, December, January (best) and until the middle of February." Apricots are the exception for pruning in January; they should be pruned in the summer after harvest. If you properly prune and care for fruit trees you will get the highest yield of fruit. A good rule of thumb is to prune plum, pluot, apple, and pear trees 15-20%; and peaches 50%.

Deciduous trees can be pruned anytime during their dormant season (in winter). Prune deciduous species, such as Western spice bush, creek dogwood, Western mock orange, red-bud, maples and deciduous oaks.

Do not prune apricot and cherry trees in winter because they are susceptible to Eutypa dieback. The best time to prune them is late August before the rainy season starts.

While you're outside pruning, remember to pick up any rotting fruit on the ground at the same time.

Pruning Tips:

Make your cuts with care in order to direct the growth for next year. Check the tree for crossing branches, broken branches, diseased wood, and old leaves and fruits. Clean out suckers, light branches, and trim the branches that grow vertically. After that, you can start to shape the tree with cuts for form and fruit production. To have an open tree with good air circulation, make cuts above outward-facing nodes. Choose nodes where you want new growth and make a cut about 1/4" above, refer to the image below.

Pruning stages
Also refer to our page on fruit tree pruning page.

Young Fruit Trees

Painted tree trunks, by Jack Kelly Clark, UC
If you have young fruit trees, particularly ones you just planted during bare root season, you want to protect them while they’re still delicate. Water them regularly while they are establishing their root system. Put mulch around the root area to hold in moisture, moderate the soil temperature, and help keep weeds from sprouting and competing for water and nutrients. Consider painting the trunk with white latex paint, diluted 50% with water. This will reflect the sun and help prevent sunburn. Sunburn is a problem because the bark can crack, allowing pests and diseases to enter the wood more easily. Once the tree is larger and has a full canopy, the leaves will normally provide sufficient protection.

More information: Video: Getting Fruit Trees off to a Good Start (88 min)

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