Ron Kujawski| Garden Journal: Why are your tomatoes cracking?


Because of drought, tomatoes are not all cracked up to be what they should be, though many are cracked up. Huh? As tomatoes ripen, many are showing concentric rings of cracks around the stem end of the fruit. Others may have deep vertical cracks progressing downward from top of the fruit.

These cracking problems are physiological, that is, they are not caused by fungi or any living organism. The primary cause of the cracking is uneven moisture levels in soil. During a prolonged dry period, when soil moisture is deficient, development of tomato fruit slows drastically. With a sudden increase in soil moisture as a result of heavy rain or over-abundant watering, the tomato fruit expands rapidly, causing the fruit skin to split — I had a similar problem recently with a pair of pants after overindulging at dinner. As the splits heal, they leave scars in the form of radial or vertical cracks. If the splits do not heal quickly, the fruit may be invaded by disease organisms or by insects such as sap beetles.

The degree and type of cracking varies somewhat with variety. Some varieties such as Celebrity, Early Girl, Jet Star, and Mountain Pride are resistant to cracking. However the best way to prevent cracking is to keep soil evenly moist through the growing season by watering and mulching the soil around tomato plants. By the way, tomatoes with cracks can be eaten if you cut around the cracks.

Get crackin' on these tasks:

• Add Echinacea, Rudbeckia, Monarda, and Coreopsis to the list of drought tolerant herbaceous perennials. It's not too late to buy and plant container-grown perennials. However, these plants don't instantly become drought tolerant. They'll still need moisture to get their roots established. Also, perennials planted now should be shaded for several days and anytime they show signs of wilting.

• Squash the squash bugs. The bugs are feeding on cucumbers, melons, pumpkins, and summer and winter squash; that's not good. Meanwhile, crows feed on the squash bugs; that's good. However, when crows peck at squash bugs sitting on cucumbers, etc., they poke holes in the fruit; that's not good.

• Pinch off the blossoms and shoots tips of pumpkins, melons, and winter squash. Any fruit that sets from this point on is not likely to have enough time to develop to maturity before fall frost. By removing new flowers, the plants will divert nutrients to existing fruit on the plants and hasten their development. As a possible side benefit, pinching off shoot tips on the vines is said to deter squash bugs since they prefer to deposit their eggs on new growth; that's good.

• Do not prune tomato plants as a means of speeding up ripening. Removing stems and leaves to expose fruit to sunlight will not hasten ripening. Furthermore, sudden exposure of fruit to bright sunlight can cause sunscald, a condition characterized by appearance of a white blotch or blister on the fruit. This eventually causes the fruit to rot. Leaves are a tomato's sunscreen.

• Take some time to meditate. The best way to meditate is on your hands and knees between plants in flower borders or astride rows of vegetables. While meditating, pull up weeds, especially those with developing seed heads. There is a meditation session scheduled in my vegetable garden this weekend for anyone who would like to attend.

• Want to learn more about best gardening practices from university professors, horticultural professionals, and experienced gardeners, and teach others your newly acquired skills? Then sign up for the 2017 Western Massachusetts Master Gardener training class. The deadline for applications is Sept. 19. For details, go to:


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