Sunday, March 27, 2011

Back in Black....Berry

This weekend I participated in the Carolina Yard Gardening School, put on by the Tri-County Master Gardeners here in Charleston. Other than working with the Coastal Carolina Camellia Society, Projects and Outreach Committee and being a general floater, I was one of the instructors for the day. My subject, Growing Fruit in the Lowcountry. I spoke on growing some twelve different kinds of fruit, from Citrus to Figs and Loquats to Grapes. One of the fruits that I actually got many questions about though, was Blackberries. So I thought maybe there was something going on and it might be a good idea to discuss them here today.
The Blackberry is considered a herbaceous (characteristic of a herb) to woody perennial and belongs to the Rose family.
They are divided into classes by their growth habit and are described as trailing (where canes are not erect and require a trellis for support), semi-trailing or semi-erect (canes are partially erect but require a trellis for support) or erect (which produce self-supporting canes).

The trailing varieties (sometimes called dewberries) are thorny, the semi-trailing (semi-erect) varieties are thornless, and the erect varieties may be thorny or thornless.
As a rule, the erect varieties are more cold-hardy than the trailing or semi-trailing varieties. Erect varieties also fruit about one month earlier than other varieties.
Blackberries prefer full sun and a well-drained soil. Typically, they grow best in temperate climates and are listed as growing in Zones 5 through 10. However, according to the United States Department of Agriculture (USDA), some type of Blackberry species can be found in every one of the 50 states.
Plants should be set out at least 2 feet apart in rows 7 feet apart. Unless you do like I do and grow them in containers. Don't believe me?
I use a teepee type of support, there are many different types of trellis systems available. Each type has its advantages and disadvantages, and most can be modified to suit your needs and growing space.
You will need to prune these very fast growing plants as they will take over a garden if not done. The first step in pruning Blackberries is to understand their growth cycle. Blackberries have crowns that produce biennial shoots (live for 2 years, then die). In the Spring, after the new flush of leaves start, I prune the spent canes all the way to ground level. I wait until the leaves come out so I can tell what is dead and what is alive.
A very important thing to remember is that a lack of water while setting fruit or during harvest can seriously reduce productivity. Water is the most critical factor for optimal fruit growth. It is also very important because it can negatively impact both the current seasons and the following years crops. They require about 1 inch of water per week, whether it be from the sky or from a hose. Nearly all of the moisture used by Blackberries comes from the top 6 inches of the soil, which is the primary rooting zone. That does not mean there are not deeper roots than that, so you still need to water thoroughly. Mulches can be used to conserve some moisture.
To get the pretty flowers as seen above and the soon to follow fruit, most Blackberries respond well to an early Spring fertilization with an all-purpose fertilizer such as a 10-10-10, or a 16-16-8. After they are done producing fruit for the season, add a small amount of nitrogen fertilizer, such as good dose of Fish Emulsion, to stimulate growth.
As long as I am talking about flowers, it is good to know that, nearly all Blackberry cultivars are self-fruitful, meaning that you only need one to get fruit.
The fruit is ripe and at peak flavor when they begin to turn a very dark, deep red/purple (black in appearance) lose their glossy shine and turn slightly dull.
You will want to pick your berries about every two to three days once they start to ripen, this will also help keep the birds from stealing your harvest.
As a general rule, insect problems on Blackberries are minimal. Pests like aphids, Japanese beetles and spider mites can be controlled on an as-needed basis with general pesticides.
Diseases include rusts, fruit rot and "double blossom." You can control fruit rots with a fungicide approved for Blackberries. Rosette, or "double blossom," is a disease that causes the shoots to have a bushy, broom-shaped appearance on the tips. These shoots produce abnormal blossoms that will not mature to fruit but will produce spores that infect the new growing canes. Again, fungicides can be used as a preventive spray.
Please follow all label instructions, it is the law!
There are many varieties of blackberries available out there, you will just have to check and see what is available in your area.
I mentioned earlier that there seemed to be a lot of buzz about Blackberries lately and maybe it is because of their health benefits. One serving of Blackberries (about one cup) provides 50 percent of your vitamin C, and 22 percent of your required daily fiber. Blackberries are also a good source of potassium, calcium, and iron. In addition, the compound ellagic acid, identified as an anticarcinogen, is found in Blackberries. I just like Blackberries because they are easy to grow, will produce berries for 15 to 20 years if you take care of them, make a fantastic jam, and just happen to have my favorite color in their name!
Happy Growing!


  1. Totally agree on this one Darren. I grow several varieties of thornless (in the ground) and we eat them as fast as they produce. Have you tried the new primocane blackberries out of Arkansas? I put out two varieties last year and PrimeArk45 this year. Don't know how they'll do in this area, but I would be thrilled with a second later season of berries on the new canes.

  2. Thanks for this informative post, I've been considering planting blackberries but don't have a good permanent home for them at the moment. Glad to see that you have success growing them in containers. Can you share your favorite varieties for container growing?

  3. They're growing wild all around my house. The flowers are beautiful right now. I can't wait to race the birds to the fruits soon.

    My papaya that I purchased at last year's Carolina Yard (it's indoors) has just started to bloom. YAY! Is there anything I can do to improve my chances for fruit to set?

  4. Hey Professor, No I have not tried the new ones out of Arkansas. I will have to see if I can locate some to try. Let me know how they do for you.
    Diana, the varieties Chester and Black Satin seem to do the best for me. I am sure there are others out there, just haven't tried them yet.
    I am also having success with Boysenberry, which is suppose to be a type of Blackberry....I always thought it was a separate type of fruit.
    Dorothy, Girl, I may some bad news for you.
    Some plants bear only short-stalked female flowers, or bisexual (perfect) flowers also on short stalks, while others may bear only male flowers. Some plants may have both male and female flowers. Others at certain seasons produce short-stalked male flowers, at other times perfect flowers. This change of sex may occur temporarily during high temperatures in midsummer. Male or bisexual plants may change completely to female plants after being beheaded and allowed to regrow. Certain varieties have a propensity for producing certain types of flowers. For example, the Solo variety has flowers of both sexes 66% of the time, so two out of three plants will produce fruit, even if planted singly. How pollination takes place in papayas is not known with certain. Wind is probably the main agent, as the pollen is light and abundant, but moths may assist. Hand pollination is sometimes necessary to get a proper fruit set. I would imagine bees are responsible also, so if I was you, I would go out there with a small paintbrush, buzz like a bee and touch each and every flower twice. Wish I could be a bearer of better news.