It's December and ‘tis the season to…think about blackberries! Our cool northern California coastal areas provide the perfect climate for growing sweet, flavorful blackberries. So take a break from the holiday rush and get going on summer's delicious crop. Here's how to have a bountiful harvest.

About Blackberries

There are a number of hybrids and also thorny and thornless varieties but, ultimately, there are two basic types of blackberries: trailing (with canes that are not self-supporting) or erect (with stiff, arching canes that are somewhat self-supporting.) Both types benefit from a trellis support and all varieties have similar growing requirements. To do their best, blackberries (also known as caneberries, bushberries and dewberries) need to be in a location that receives partial sun and in soil that is slightly acidic with a pH of about 6 to 6.5. Ensure that the soil is rich in organic matter and topped with a layer of organic mulch. Plants will need regular irrigation during the growing season so carefully check the soil at the base of the plant to determine if watering is sufficient. Root areas should be cool and moist but not wet and should not be allowed to dry out.  Once established, apply compost or manure in late fall or early winter to allow rain to leach excess salts and as soon as the plants begin to put forth new growth in early spring, apply an organic granular fertilizer (20-20-20) around the base of the plants. This will provide the nitrogen needed for vigorous growth and fruit production.

How and What to Prune

A blackberry plant can live for many years but fruit grows only on the short lateral shoots of two-year-old canes  (“floricanes”)which then die back after berry production is over. In spring, you can “tip prune” to force the canes to branch out and create more lateral shoots for fruit to grow on. Use sharp, clean pruning shears and cut to about 24 inches. If the canes are shorter than 24 inches, prune the top inch of the cane. In the fall, after fruiting is complete, prune to remove diseased, dead and spent canes by cutting to ground level. This will encourage the plant to produce more first year canes (“primocanes”), which will mean more fruit-producing canes the following year. If you already have blackberry vines, prune them now.

How and When to Plant

December and January are good months to plant dormant blackberries, but potted vines can also be planted in spring or summer. For bare root plants, trim the dead roots and dig a planting hole just large enough to accommodate the roots. Cover the roots with soil and press firmly to remove air pockets. Water thoroughly to settle the soil. After planting, cover the soil with mulch. Blackberry cultivars can be spread 3 to 4 feet apart in the row with 8 to 10 feet between rows. Cut the canes on newly set plants to 6 inches at planting time.

When to Pick

Blackberries do not continue to ripen once they are picked so it's important to pick fruit at the peak of flavor and sweetness. Since different varieties ripen at different times, you can extend your berry season by planting a few different kinds. Erect blackberry cultivars include: Black Satin, Cherokee, Cheyenne, Chester, Darro, Hull Thornless, Shawnee, and Triple Crown. Trailing blackberry cultivars include: Boysen, Kotata, Logan, Marion, Ollalie, and Silvan. (More information: https://ucanr.edu/sites/gardenweb/Berries/?uid=4&ds=466).

Troubleshooting

Purchasing certified disease-free plants from a nursery is a good practice. Although it is easy to propagate your own berry plants from canes, plants derived from another garden or grown near wild blackberry bushes could introduce unwanted diseases. If your blackberry plant looks healthy and blooms, but grows misshapen fruit or no fruit at all, chances are that your blackberry plants are affected by a blackberry disease. If you have more than one variety, one type may fruit while another, susceptible variety may not. On the coast, Anthracnose is a common fungal disease that tends to attack plants when the weather is cool and wet. The fungus can be spotted when the blackberry fruit starts to ripen but then wilts or turns brown.

If you decide to use a fungicide, it's important to determine if a fungus is indeed the culprit. Since symptoms could be due to something other than a fungus, using a fungicide might be a waste of money and do more harm than good. Contact the UC Master Gardeners Helpline (Phone:  (650) 276-7430; Email: mgsmsf@ucanr.edu), to provide information and a photo of the problem. The Helpline will help determine if using a fungicide is necessary and, if so, what types of safe fungicides are best to use.

Insects (aphids, cutworms, thrips, mites, etc.) can also cause fruiting problems with blackberry plants. Check the bush carefully, particularly the undersides of leaves to see if the plant has unwanted pests. It is important to first identify the pest before determining the treatment. Sometimes the treatment could be as simple as hosing off aphids or spraying the pests with soapy water. Detailed information about blackberry diseases, pests, and treatments can be found here:  http://ipm.ucanr.edu/PMG/GARDEN/FRUIT/blackberries.html

Cynthia Nations is a UC Master Gardener who continues to experiment with different blackberry cultivars coast side. This article was edited by UC Master Gardener, Maggie Mah.

Ripe, juicy, sweet blackberries: what's not to love? Blackberries are grown for us to eat and enjoy, but some species can be considered weeds when they take over home landscapes, roadsides and waterways, and other areas. The most problematic species are the introduced wild blackberries, cutleaf blackberry and Himalayan blackberry. Blackberries can be highly competitive, smothering existing plants with their dense stands. Accumulation of dead stems can create a dangerous fire hazard. 

In urban landscapes, blackberry brambles can create habitat and food for wildlife and birds, but also for rats and other pests. When invasive wild blackberries take over a landscape with their thorny, fast-growing stems, the fruit may seem less loveable. However, since people enjoy the fruit, wild blackberry plants can be controlled to a desired level. 

The newly revised Pest Notes: Wild Blackberries, authored by UC Cooperative Extension advisor Scott Oneto and emeritus UC Davis weed scientist Joe DiTomaso, includes detailed descriptions of the wild blackberry species found in California, as well as information on how to control blackberry populations using mechanical and updated chemical management strategies. 

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By Susanne von Rosenberg, UC Master Gardener of Napa County

 

 

One of the joys of summer is being able to harvest fresh, perfectly ripened fruit from your own garden. December and January are the best months to plant bare-root fruit trees and berries so you can enjoy the bounty in summers to come.

 

Unlike fruit trees, most berries provide a quick return on your efforts. Strawberries bear fruit the same year you plant them, and blackberries and raspberries produce the year after you plant them. Blueberries are more complicated to grow (they need acidic soil to thrive), but also usually start to produce some fruit in the second year.

 

Berry plants are less expensive than fruit trees, and if you choose the right kinds, you can expand your berry patch over time. The main drawback to berries is that they all have relatively high water needs.

 

Brambleberry is another name for blackberries and raspberries. Boysenberries, marionberries and ollalieberries are all varieties of blackberries. Blackberries are well suited to our Napa Valley climate. (In fact, boysenberries were developed here.) Raspberries also do well in all but our hottest areas.

 

While it's easy to get blackberry and raspberry seedlings from friends (many brambleberries produce suckers from their roots), it's best to start with certified disease-free nursery stock. You can always expand your berry patch by planting some of the suckers. Blackberries and black and purple raspberries also tip-root. If the tip of a cane touches moist ground, it will grow roots from that tip.

 

To produce well, brambleberries should be planted in full sun. In hotter areas, raspberries benefit from some afternoon shade. Care of brambleberries is fairly simple. Fertilize them once a year at the start of the growing season and keep the soil moist, not soggy, throughout the growing season. The berries also need pruning each year.

 

Blackberries yield fruit on canes that grew the previous year. The canes growing in the current year are called primocanes. Nurseries sell both erect and trailing varieties of blackberries; trailing varieties need a trellis. Erect varieties have sturdier canes, but the canes will still tip over when they get long, so these varieties also benefit from a trellis. Install trellises when plants are small to minimize root damage.

 

Most blackberry varieties have thorns, but there are thornless types. I used to be suspicious of thornless varieties, assuming that I would have to sacrifice flavor or vigor for convenience. A couple of years ago, I finally tried a thornless variety, Triple Crown. I was happily surprised by the great flavor and vigor, both of which compare favorably with the boysenberries I have been growing for a long time. To extend your harvest, choose blackberry varieties with different ripening periods.

 

Raspberries come in four colors: red, yellow, purple and black. The cultivation process for yellow and red raspberries is the same. Red raspberry varieties come in two types: summer bearing and fall bearing. Summer-bearing raspberries produce canes that grow one year, then primarily bear fruit the following year. Summer bearers produce some fruit on the tips of the current season's canes, but a larger crop is produced on one-year-old canes.

 

Fall-bearing raspberries do the opposite: they bear large crops on the top parts of the current season's canes in late summer and fall. If left to overwinter, canes bear a second crop in the spring, on the lower portions of the canes that fruited the previous year.

 

My new favorite red raspberry variety is Nova. It is vigorous, has great flavor and has consistently been the earliest and latest producer in my raspberry patch.

 

Black raspberries (you may have heard them called black caps when you were growing up) and purple raspberries grow on arched or trailing canes. Black and purple raspberries only sprout new canes from the crown (the base of existing canes) or through tip-rooting. Fruit grows on laterals coming from the main canes, so they are pruned differently from blackberries and red raspberries.

 

To keep your berry patch fruitful, prune out the old (non-fruiting) canes and excess canes. Remove fruiting canes of blackberries and summer-bearing raspberries after they are done fruiting. Then tie up the primocanes.

 

For trailing varieties, cut the new canes to 8 to 10 feet and loop them around the trellis wires. Fall-bearing raspberries can either be cut to the ground after the fall crop, or you can cut off the top portions of the canes that fruited and get a small spring crop on the lower parts of the canes.

 

Prune black and purple raspberries to a height of 24 to 30 inches after fruiting. In early spring, cut back any laterals that sprouted to 8 to 10 inches. During the dormant season remove all dead, damaged, weak and diseased canes from all brambleberries. Remove all but 4 to 5 of the most vigorous canes from the crowns of black and purple raspberries and 8 to 10 canes for blackberries. Aim for 4 to 5 strong canes per foot for red raspberries. With the right care through the year, your berries should provide a bountiful harvest.

 

Napa Library Talks: First Thursday of each month. Register to get Zoom link. Thursday, January 7: Bare Root Basics.

 

Free Rose Pruning and Winter Care Workshop: Saturday, January 9. Register for the Zoom link.

Got Garden Questions? Contact our Help Desk. The team is working remotely so please submit your questions through our diagnosis form, sending any photos to mastergardeners@countyofnapa.org or leave a detailed message at 707- 253-4143. A Master Gardener will get back to you by phone or email. For more information visit http://napamg.ucanr.edu or find us on Facebook or Instagram, UC Master Gardeners of Napa County.

 

This summer remember that fruits are easy to freeze. Many you don't need to blanch or do much to other than wash, dry and perhaps add sugar to (for the best product). Local small berries, if you grow them, are probably past picking, but they are still available in markets. If you can drive up to the mountains or further north, picking both wild and farmed berries should be going on

Summer berries, especially those you pick yourself, or grow yourself, are so much better than those usually sold in stores. If you go somewhere to pick, you are in control of how ripe those berries are. If you plan well you can pick in the morning and have those berries in the freezer or in a jar that evening. Preserving doesn't get much more immediate than than--unless you get the fruit from your own backyard or from a neighbor.

Small berries such as blackberries or blueberries can be washed, dried, placed in a single layer in a flat pan and individually frozen dry or with a little sugar. Place them in freezer containers or freezer bags and you can pour out whatever you need when you need it.

 

 

Fresh, ripe melons are fantastic, of course! But melons such as honeydew and cantaloupe can be frozen. Place chunks in the freezer at the height of the season so that you can eat a bit of summer during the winter.

 

 

 

 

Grapes are great frozen whole in to eat as a sweet, cold treat. Taste first to make sure you are freezing the sweetest ones and they will taste fantastic frozen. Of course you can freeze them in a puree if you want to make some jelly during the winter to warm your home up! And remember grape jam or jelly.

 

 

 

 

 

And one last "for instance": don't forget pineapple. Pineapple on sale can be very sweet and cost-effective to freeze. Freezing pineapple is fast too--no sugar needed, just wash, peel, cut it up and freeze. Of course you can jar it up yourself.

 

 

 

 Also, don't forget our upcoming classes: