2018-04-11 / Agriculture and Outdoors

Get a head start with zinnias

By Calvin Finch

Zinnias are a favorite for providing attractive color to flower beds in South Texas. Zinnias are a favorite for providing attractive color to flower beds in South Texas. Q. The snapdragons and dianthus in our flowerbed are beautiful. How much longer will they last before the heat is too much for them? As attractive as the winter annuals are, I am anxious to plant zinnias!

A. The snaps should last through April and the dianthus will last even longer, often through May. The zinnias will do well even if you wait and plant them in May or June. Another option is to get a head start with the zinnias by removing some of the rows of snaps or filling every gap with zinnia transplants.

Q. There is a weed coming up in my lawn that has a small yellow flower and a small mouse-ear shaped leaf. It only grows to about 6 inches tall. What is it and how can I control it?

A. It is called horseherb and is very difficult to control because it is a perennial that reproduces with seed. A broadleaf contact herbicide may kill it back, but it is a persistent weed that can bloom year-around if there is enough soil moisture. Horseherb generally prospers in lawns that are growing in poor compacted soils in sun or partial sun. It is accepted by some gardeners because it mows well, the deer like it as a food source, and black swallowtails use it as a nectar source. It will also become established as a winter weed in raised bed gardens. Good luck controlling it!

Q. The Monarchs have arrived in my neighborhood, but the milkweed has barely begun to grow. Does that mean that they won’t lay eggs in the area this spring?

A. The milkweed does seem behind schedule in some locales because of the cold weather in January but it grows fast once it starts, so over the wide area of the South that the initial migrants cover, should provide egg-laying sites in April. Both the tropical and common milkweed in gardens in my neighborhood are sprouting.

Q. Our spinach has been very productive this winter but now it is covered with a mildew type coating and is unappetizing. Is it time to pull it for the compost pile?

A. Yes, it sounds like it. Most of the winter greens have gone to seed or have the foliage problems you describe. Even the foliage of the Swiss chard is turning bitter from the heat. Pull it up to make room for the green beans, peppers, cucumbers, cantaloupe, summer squash, and tomatoes.

Q. Our neighbor put in a new zoysia lawn this winter. He had an extra 1,000 sq. ft. of sod and gave it too us. We did a rush job of laying it and now it is very uneven. We should have rolled it. Can we even it out with sand?

A. I don’t believe it is too late to roll the lawn now. After rolling it, apply a thin layer (5 inches) of top dressing to level the lawn and fill any gaps between sod layers. Top dressing includes both sand and compost.

Calvin Finch is a retired Texas A&M horticulturist. Hear him on “Gardening South Texas” on KLUP 930 AM radio Saturdays and Sundays from noon to 2 p.m. Or, email him at

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