Garden q&A: pollination vital to veggies
Question: We are very puzzled why our zucchini did not take this summer. The six plants seemed hardy when they were planted. They were put in the exact same spot as the previous two years. Mushroom manure was put on the soil like the previous two years. They did get sun and were watered periodically when we did not have enough rain. All summer, there were large yellow blossoms — but no zucchini! What could have happened?
Answer: You are facing a problem that many members of the cucumber family have suffered from in the past few years.
From your description, I suspect that poor pollination is at play. Sadly, gardeners and farmers everywhere are facing pollination issues due to the decline of both the European honeybee and many native bee species.
This issue is often noticed by gardeners when plenty of flowers occur but fruit fails to set (and, yes, zucchini is botanically a fruit). Or when the fruit begins to form, but its growth slows or stops before it reaches maturity. Often with zucchini and other members of the cucumber family, the fruit will have lopsided growth. The blossom end will swell while the rest of the fruit will simply wither away.
To stave off pollination issues in the future, interplant your vegetable garden with lots of flowering plants. Herbs and flowering annuals like sunflowers, cosmos, zinnias and others draw pollinators of all sorts to the garden, where they'll not only visit the ornamental flowers but also the vegetable plant blossoms.
Another problem your plants may be facing is soil-related. I suggest you have your soil tested this fall to access its pH and fertility. Mushroom soil is fairly alkaline (its pH averages 8.0), and with regular additions such as yours, it can alter the soil pH, making some nutrients unavailable to the plants.
Poor nutrition also may be at play in your garden, but the only way to know for sure is to take a soil test.
You also should avoid planting your zucchini in the same location each year. Crop rotation, even on the smallest scale, can greatly benefit vegetables of all sorts.
As zucchini are often targeted by squash vine borers, finding a new spot each year can make it harder for the newly emerged pests to locate the plants each spring.
Squash vine borers can be thwarted by wrapping the lowest 3 to 4 inches of each plant with a strip of aluminum foil immediately after planting. Nestle the edge of the foil just beneath the soil surface, as this is the most vulnerable point on the plant. Female vine borers will not lay eggs on the foil.
Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio. She is the author of several gardening books, including “Grow Organic” and “Good Bug, Bad Bug.” Her website is www.jessicawalliser.com.
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