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Ask Dr. Hort: Blessed Lisianthus, darned Bermuda grass, stubborn garlic

 
Published March 31, 2012

It makes an annual splash

Q: The Tampa Bay Times had a photo of Balboa Blue Rim Lisianthus several weeks ago. Can you give me a bit of information about it? Betty Schaaf

A: Lisianthus "Balboa Blue Rim," Eustoma grandiflorum, is one of many cultivars (cultivated varieties) raised for the annual garden or containers. They should be planted after danger of frost is over. They last well as a cut flower and continue flowering for about eight to 10 weeks. Make sure to deadhead any spent blooms to keep the plant flowering.

It's simply hard to grow garlic in Florida

Q: In Louisiana, garlic was planted in April and in November. I got beautiful, large garlic. Now in Florida, I used the same planting schedule and get garlic smaller than a penny. The garlic was shaped beautifully, but the size was awful. When would you suggest I plant in this state? Condo gardening is small, and Florida soil is much too sandy. Potting soil was purchased and garlic was planted in an Earth Box. Jacqueline Durand

A: You did nothing wrong. Garlic simply doesn't like to grow this far south.

Use potting mix, no manure, in Earth Box

Q: I read an article about tomatoes and too much nitrogen in grow boxes. I have an Earth Box, in which I put soil with cow manure. These plants did not do well at all. Is soil with cow manure suitable for these plants? G.Walsh

A: There is always a controversy between "potting soil" and "potting mix." For most applications concerning container gardening, "potting mixes" are preferred. Potting mixes contain peat moss as the base with vermiculite, perlite and moisture-retaining materials such as Terra-Sorb, and are very lightweight, which provides adequate moisture with good drainage. Potting soil contains fine sand, muck and clay components, making it heavy with poor drainage. Your Earth Box is designed for potting mixes to be used as the substrate. The following is a link for suitable products, earthbox.com/approved-growing-media.asp. Cow manure, by itself or with soil, would be heavy with poor drainage; hence your crop failure.

Repeated attacks can tame Bermuda grass

Q: What are these weeds and how can I get rid of them? Several years ago I decided to xeriscape my yard. I put in drought-tolerant plants and mulch. These weeds grow through everything. I have pulled them, put down newspaper and mulch. The next year I pulled them, put down cardboard and mulch. If I can't get rid of them I am going to pull up all my plants, mow the weeds and call it a lawn. Mary Dunn, Dunedin

A: The pictured weed that seems to be driving you insane is Bermuda grass, Cynodon dactylon, which belongs on the golf course, where it is manicured into tees, fairways and greens, but in your xeriscape garden, it can be the weed from hell. It is a perennial grass with white wiry horizontal, branching stems that grow underground (rhizomes) and just above ground (stolons), with thin grass blades. Many people call it wire grass and will win the battle if hand pulled.

For optimum control you need to apply a grass selective herbicide with the active ingredient sethoxydim (Grass Getter) or fluazifop (Ornamec, Grass-B-Gon). These products will kill the grass without injuring your ornamentals if applied according to label directions. Beginning this spring, as it begins growing, spray it. Applications will be needed for every 6 inches of growth until you win the battle. The products kill the roots, stems and leaves, giving you complete control and enabling you to leave your xeriscape garden intact!