August 30, 2014
1 - Blackberry plants often reproduce themselves by tip layering, but be careful that you do not violate plant patent laws by propagating and distributing patented varieties.
Yard and Garden August 30, 2014
I started a small blackberry patch this past spring and was amazed to see one branch fall down on the soil and take root. If they are that easy to root, I thought why not, when I prune the plant this next time, start some cuttings and have more blackberry plants for myself and for family members.
But I received an instruction booklet from a nursery which says, regarding blackberries, "After fruiting each year, the old canes should be cut out and burnt." The fact that they use the word "burnt" is confusing to me. Is there some reason I should NOT try to root some? Must they be burnt instead of simply disposing in the garbage, along with grass clippings?
-Betty J. H.
Blackberries often naturally reproduce by "tip layering", which is what you may have observed. The ends of the blackberry cane push themselves into the ground and form roots. The buds in the buried tip will grow upwards in the spring producing a new plant. Blackberries may also be propagated by stem cuttings. This may be difficult in our dry environment, but gardeners on the internet describe it as easy. If you have a greenhouse, or some way to keep the cuttings from desiccating, they may succeed. I suspect that many of the gardeners on the internet telling how to grow blackberry cuttings are gardening in much milder and much more humid environments.
Blackberries may also increase themselves by producing "suckers". Sucker is the horticultural term for plants growing from adventitious buds formed on roots. Plants produced this way can be used to increase the number of plants in your garden row, or dug up and moved to another area.
There are two reasons that you found information about burning the canes after pruning them from the plant. However, before you prune your blackberries let me point out that most blackberries do not flower or produce fruit on a cane the first year. The first year canes are called "primocanes". They are vigorous, they may tip layer, and may be used to collect cuttings, but they do not flower in most varieties of blackberries. In the second year, that same cane is called a "floricans" because it produces flowers and fruit its second year. Do not prune away your primocanes. Prune the floricanes after you have harvested fruit. They will die back anyway after producing fruit. However, these may not work well at producing new plants from cuttings.
Now, the reason to burn the canes is first to prevent the spread of diseases. In our dry climate, diseases are not a major problem, but removing the old floricanes and burning or removing them from the garden is wise.
A second reason for destroying the old canes instead of taking cuttings is because many of the new varieties of blackberries are patented and propagating them for distribution is prohibited. I talked to Dr. Kevin Lombard, NMSU Associate Professor of Horticulture at the Agricultural Science Center at Farmington, about blackberries. He is conducting research with blackberries, grapes, and other crops. He stated, "With some grape cultivars I receive for trials at the NMSU-ASC Farmington, I am required to sign an agreement with the nursery indicating I will not propagate vines for distribution. I assume the same would apply to blackberries that might be patented." A person or nursery that develops a new variety of fruit has a right to protect their variety for 20 years with a plant patent in order to recover the cost of developing the variety and to derive some profit. This provides an incentive to continue producing new varieties for us. Plant patents protect plants that are clonally propagated as we have described for blackberries.
Dr. Lombard's research with blackberry cultivars is fairly new, but he said he is currently evaluating the Arapaho, Navajo, and Chester cultivars. We will look forward to the recommendations that come from his research. I grow Chester in Albuquerque because that was one of the varieties recommended by Dr. Ron Walser, NMSU Extension Horticulture Specialist, retired, based on his work at the NMSU Los Lunas Agricultural Science Center.
Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: firstname.lastname@example.org, office: 505-865-7340, ext. 113.
For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms.
Please copy your County Extension Agent and indicate your county of residence when you submit your question!