Weekly Express-News Article

By Calvin R. Finch, PhD, SAWS Water Resources Director, and Horticulturist

Saturday, July 26, 2008

“Fall Tomatoes and Marigolds”

It is too hot outside to easily think about a fall vegetable garden, but temperatures do begin to fall in August and if you want fall tomatoes it is time to consider planting them. The nurseries have transplants ready for the garden.

Rumor has it that there will a limited number of Surefire tomatoes on the market this season. They are my favorite choice for the fall garden. Surefires are a determinate, heat setting variety that produce a relatively small plant, stop growing and concentrate on producing fruit over a short season. Surefires are the best bet for producing and ripening tomatoes before the first frost. The tomato is tennis ball size and firm. Other choices available in area garden stores are Celebrity, Solar Fire, Sun Pride, 444, and Amelia. They take longer to produce fruit than Surefire, but have a reasonable chance to beat the cold weather, especially if you are willing to protect them from the first frost. Have the blankets and a heat source ready for action.

Producing autumn tomatoes often requires that you also be ready to harvest full size fruit before it turns red. Tomatoes that have changed color from green to a light orange, or even a whitish green are physiologically ripe and will turn red in your kitchen or store room.

It is important to water tomato transplants, placed in the garden when it is this warm, every day. Mulch them with a shallow layer of leaves and use drip irrigation or a soaker hose. If you do not have a soaker hose, you will have to be prepared for hand-watering every evening or morning. Remember, tomatoes are high fertilizer users. Spread a cup of slow release lawn fertilizer over every nine square feet of ground around the plants.

Another plant that prospers when placed in the garden in late July and early August is the large flowered American hybrid marigolds. Some of us still call them “Marimums” because they have the same impact as garden mums in the autumn landscape. Actually, the performance is superior because the blooms are larger and they last longer. Another advantage is that you do not need to provide garden space all year for a bloom period in the autumn. Mums are nice, but try fall marigolds.

To maximize performance there are a few hints to consider. Do not buy Marimums that already have their blooms open. Seek out sturdy dark green plants that are not showing color yet. The plants you buy can have buds, but if a large number of flowers are open, the plants will not grow any larger. To have the best show of color in the garden, large plants that develop in place are best. Plant them from 12 – 18 inches apart in blocks for the most impact. Yellow or orange work equally well.

Marigolds do not seem to be affected by nematodes. They can be planted on infested sites. In fact, planting the small varieties of marigolds (dwarf-type) close together on an infected site seems to reduce nematode populations. Marigolds perform better in the autumn than the spring because temperatures are cooling and spider mite generation time increases as the season progresses. Grow marigolds with the same care in general as tomatoes, but they require less water and fertilizer as they mature.