Gardeners Checklist: Here Is What to Do on the Week of July 22

By Ron Kujawski

* Do not apply weed killers during this heat wave. Many herbicides are volatile and the fumes can cause injury to non-target plants. For that matter, don’t apply any pesticides in very hot weather. Read the label for specific precautions.

* Sow seeds of leafy greens for harvest in September. Try some leafy Asian vegetables such as Chinese loose-leaf cabbage "Crispy Choy," Chinese broccoli (also called Gai Lohn), and mizuna. All mature in about 45 days or less. Seeds may still be available at garden centers.

* Stake pepper plants. They tend to get top-heavy this time of year and their brittle stems are prone to snapping at their base.

* Check grapes for early color development. If grapes are turning color now, it is not due to ripening. Rather, pre-mature color is a symptom of a disease called black rot. Promptly remove the affected grapes and discard or bury them.

 * Sow seeds of pansies now in a cold frame or prepared seedbed in a corner of the garden. Keep the soil evenly moist and the seedlings shaded. In late fall, cover seedlings with pine boughs or straw. Early next spring, transplant seedlings to the flower garden or window boxes.

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And now, the “Saga of the Ugly Tomato!” It was a dark and stormy night … or was it a sunny and hot day? It doesn’t matter because environmental extremes of one sort or another often result in some pretty ugly tomatoes. Take for example tomatoes with dark brown or black, sunken, leathery spots at the bottom or blossom end of the fruit. Pretty ugly! This is blossom end rot, caused by calcium deficiencies related to prolonged dry periods or cycles of very wet and very dry soils. Next, we have tomatoes with white patches on the side of fruit directly exposed to intense rays of sunlight. This is sunscald. It typically occurs when plants are pruned or leaves are removed, leaving fruit exposed to sun on hot, dry days such as is common this summer. Pretty ugly! With this current heat wave and bouts of heavy rain, expect to see cracks in the skin of tomato fruit due to rapid water uptake. These cracks may appear as concentric, circular cracks around the top of the fruit, or as cracks originating near the stem and extending down the fruit. Pretty ugly! Next, we have tomatoes that are gnarly, puckered or otherwise mis-shapened, particularly around the blossom end of the fruit. This is called catfacing. It is most common on large, fruited varieties such as Big Boy, Brandywine and Big Beef. Exposure to chilly temperatures at the time blossoms are forming can cause catfacing. Tomatoes set out in late May when nights were very cool are most likely to have catfacing. Pretty ugly! I better stop now before this column gets any uglier.

Ron Kujawski began gardening at an early age on his family's onion farm in upstate New York. Although now retired, he spent most of his career teaching at the UMass Extension Service. He serves on Berkshire Botanical Garden’s Horticulture Advisory Committee. His book, Week-by-Week Vegetable Gardener’s Handbook, is available here.