Rotating Crops in Vegetable Gardens

Rotating Crops in Vegetable Gardens

Q. I understand that rotating crops in a vegetable garden can help cut down on insect and disease problems. Should I apply this method to my small backyard vegetable plot?

A. Many insects and diseases attack plants within the same family. If you have had problems with a particular pest or disease, try planting vegetables from another family in that section of your garden. Veteran vegetable gardeners often rotate their crop plantings every two years to safeguard against pest problems.

Starting tomatoes indoors

Q:  How do I start tomato seedlings indoors?

A:  To grow your own tomatoes for transplanting outdoors, sow the seeds indoors four to six weeks before the usual last frost (around May 15 in the Chicago area).

Use a sterile seed starting mix and any containers that will hold soil, provide drainage, and accommodate growing roots. Moisten the soil, place two seeds in the pot, and cover lightly with more soil mix. Cover the pots with clear plastic to keep the soil evenly moist and place the plants in a warm location until germination occurs.

Disease and insect resistance in tomatoes

Q:  What do the letters VFNT mean on the tomato plant labels?

A:  Tomatoes are prone to a number of diseases and pests. Tomatoes have been hybridized to be resistant to common problems. The following letters represent disease/insect resistance and may appear alone or in a combination:

V = verticillium wilt resistance (fungal disease)
F = fusarium wilt resistance (fungal disease)
N = nematode resistance (insect)
T = tobacco mosaic virus resistance (viral disease)

Skin cracking in tomatoes

Q:  How do I prevent my tomatoes from cracking?

A:  The main cause of skin cracking is fluctuation of soil moisture, especially as tomatoes ripen. If soil becomes dry, and plants then receive heavy rainfall or amounts of irrigation, the plants will take up water quickly and put on a growth spurt. This type of fast growth causes the skin to crack. Tomato cracks can be avoided by applying a few inches of organic mulch around the plants to prevent the soil from becoming overly dry. The best time to water tomatoes is in the early morning. 


Composting rhubarb leaves

Q: Is it safe to compost rhubarb leaves?

A: Yes. Although the leaves of rhubarb plants contain a high level of oxalic acid and should not be eaten, they are safe to add to the compost pile. The oxalic acid degrades rapidly in the pile and has no impact on compost quality.

Planting garlic

Q:  When is the best time of year to plant garlic? Can I plant whole heads purchased at the grocery store?

A:  Garlic should be planted in early to late September in the Chicago region. Purchasing bulbs from the grocer that are not sold specifically for planting is not recommended as those varieties are not reliably winter hardy in our region. Garlic heads should be divided into the individual cloves for planting. Use the larger, outer cloves for best results.

Tomato plants don’t produce as much fruit

Tomato plant stress

Q. Last year, my tomato plants didn’t produce as much fruit as in past years. Why is this and is there anything that I can do about it?

A. There can be several reasons to explain low fruit production:

• Sometimes flowers drop off the plant during periods of fluctuating temperatures. Temperatures above 90 degrees Fahrenheit during the day can cause the blossoms to drop without setting fruit. If evening temperatures fall below 55 degrees, remain above 75 degrees, or if the humidity is too high, blossoms can also drop prematurely.

Tomato Ripeness

Ripe Tomatoes

Q. How can I tell when the tomatoes in my garden are ripe?

A. Determining when tomatoes are ripe can be tricky, especially when we are anxiously waiting to sample the first tomatoes of the season. As a practical matter, the best guides to tomato ripeness, particularly for the heirloom varieties and those hybrids bred for the home gardener, are color and touch.