Poor blackberry pollination can be traced to spring weather
This Babycakes blackberry, a patio-size plant, produced just a few misshapen
berries this spring. Weather played a large part in the problem. (Photo: Debbie
This berry season, the bees let me down. My usually dependable blackberry plants bore precious few berries. The ones that did develop turned out misshapen. Instead of clusters of berries, the canes were covered with dried-up brown stubs.
I had lots of flowers – beautiful white blooms that usually attract bees with no problem. My blackberries grow near a big bed of roses; bringing pollinators into my backyard has never been a problem.
But this spring was different. In particular, my Babycakes dwarf blackberries fell victim to rollercoaster temperatures. Early April warmth (including 92 degrees on April 8) brought out the first berry blooms. But that was followed by a sudden plunge back into the 50s and frost on April 12. That sudden, unseasonable frost may have snuffed out pollinated blooms.
Once the flowers open, their stamens and pollen stay viable for only a short period (usually three days); they need bees when they need them. Honeybees don’t like wildly fluctuating temperatures. They don’t come out when it’s too cold or too hot, and it was both while those berries needed their help.
So the little pollination that did happen was extremely spotty; my guess, it was self-fertilization, not bees.
Adding to the berry dilemma were heat and drought, especially in June as berries were ripening.
Sacramento set a record for most 100-plus days in June; 11 days hit triple digits including a streak of eight straight. Three June days reached 104. That put heat stress on plants as berries were developing.
Vines already were thirsty. The last six months have been almost bone-dry, and even those notoriously vigorous blackberry roots were subject to dieback. Unless plants got supplemental irrigation, the vines tended to brown and often aborted berry production. (My Babycakes plant has the added challenge of growing in a large pot.)
And it’s not just my poor Babycakes that’s suffering. I’ve seen a similar lack of pollination and vine dieback in blackberries in our local greenbelt.
Fortunately, my vines are already sprouting healthy green growth. It’s time to cut out the old canes with their brown stubble, and move on. Maybe I can get a fall harvest? We’ll see what the bees are doing in August.
For more on blackberries and other caneberries, here are UC cultivation notes: https://www2.ipm.ucanr.edu/agriculture/caneberries/Growth-and-Development/ Also, here's good information from the Sacramento County master gardeners on growing caneberries in our region: https://ucanr.edu/sites/sacmg/files/74193.pdf
Comments0 comments have been posted.
Sacramento Digs Gardening to your inbox.
Taste Fall! E-cookbook
Sites We Like
Dig In: Garden Checklist
For week of Dec. 3:
Make the most of gaps between raindrops. This is a busy month!
* Windy conditions brought down a lot of leaves. Make sure to rake them away from storm drains.
* Use those leaves as mulch around frost-tender shrubs and new transplants.
* Rake and remove dead leaves and stems from dormant perennials.
* Just because it rained doesn't mean every plant got watered. Give a drink to plants that the rain didn't reach, such as under eves or under evergreen trees. Also, well-watered plants hold up better to frost than thirsty plants.
* Prune non-flowering trees and shrubs while they're dormant.
* Clean and sharpen garden tools before storing for the winter.
* Brighten the holidays with winter bloomers such as poinsettias, amaryllis, calendulas, Iceland poppies, pansies and primroses.
* Keep poinsettias in a sunny, warm location. Water thoroughly. After the holidays, feed your plants monthly so they'll bloom again next December.
* Plant one last round of spring bulbs including daffodils, crocuses, hyacinths, anemones and scillas. Get those tulips out of the refrigerator and into the ground.
* This is also a good time to seed wildflowers such as California poppies.
* Plant such spring bloomers as sweet pea, sweet alyssum and bachelor buttons.
* Late fall is the best time to plant most trees and shrubs. This gives them plenty of time for root development before spring growth. They also benefit from fall and winter rains.
* Lettuce, cabbage and broccoli also can be planted now.
* Plant garlic and onions.
* Bare-root season begins. Plant bare-root berries, kiwifruit, grapes, artichokes, horseradish and rhubarb. Beware of soggy soil. It can rot bare-root plants.
Taste Spring! E-cookbook
Taste Summer! E-cookbook