How to Keep Your Lovely Lilacs Blooming!

Lilacs are lovely, demanding, easy to grow and/or misunderstood. Mike McGrath, host of You Bet Your Garden, will discuss how to care for — or leave alone- the plants that bring us that wonderful scent of  spring— or don’t. Plus your fabulous phone calls. 

Image: LtPowers

Question of the Week:

I heard you say recently that Lilacs require acidic soil, much like azaleas. I was curious about your source of information and data on this subject. A lot of us spend a lot of time, money and effort trying to get our plants to grow and live long and successful lives. It is important that we receive good and accurate information from those who purport to be experts. We look forward to elaboration on this topic.
-Tom in Greenville, North Carolina

Mike sets the record straight »

Image: Marissa DeMeglio

Highlights from this week’s show:

Charlie from Forked River, NJ is struggling to grow fruit on his tomato plants, which are staked or caged in both big containers and a flat earth garden. In an attempt to spread the pollen, Charlie stimulated the plants with an electric toothbrush, achieving only a minimal amount of success. Mike suspects that this did more harm than good. “Something like an electric toothbrush might be damaging the flowerhead…doing too much destruction for the tomato to form adequately after that,” he says. Instead, Mike suggests that Charlie take an oscillating fan and turn it on the plants in the morning so that the leaves and flowers are moving around. A battery powered camping fan would be an ideal tool to do so. “Doing that a couple days a week would be more effective…and less destructive,” Mike says. “It’s also a lot less time consuming than traditional hand pollination.”

Laura from Upperville, VA asks Mike about the use of corn gluten when treating grass surrounding the Oak Spring Garden Foundation, where she works. Since the Foundation is a botanic educational center, she hopes this organic method will combat weeds and make for a visually appealing lawn. “The most important thing is that the grass can never be cut lower than three inches,” Mike says. “The real secret to having weed-free turf has nothing to do with chemicals or organics…most of it is cultural.” This begins with making sure the grass is high enough to shade its own soil in the heat, or else the beating sun will result in an infestation of warm season grasses, like crab grass. Corn gluten meal can be applied during the spring when the soil temperature begins to approach 55 degrees about four inches below the surface. However, with Virginia lawn care laws, Laura has to be careful only to spread nine to 10 pounds of nitrogen per 1000 square feet. “You could do that once when you are approaching that [soil temperature of] 55 degrees, and again 6 weeks later,” Mike says. “That would give the grass a very strong, but natural feeding and prevent a lot of dormant weed seeds from germinating.”

Joanne from Oklahoma is an organic gardener struggling to battle peach tree borers, an insect that lays eggs in the bark of the tree. So far, she has lost three peach trees, one apricot and a plum to the pest. “We have to start out by acknowledging that this is probably the toughest crop, not only for a home gardener to grow, but even for commercial orchards,” Mike says in reference to peach trees. “If your trees are getting old, don’t be afraid to cut them down and plant new ones in slightly different locations.” Garden author Lee Reich is a good resource for problems with peach trees, like early death, pests, and improper soil. In the past, Lee has told Mike that the trees prefer acidic soil, so Mike advises Joanne to test the pH of hers. Since she lives in Oklahoma, the soil could be much more alkaline than that in the northeast. “You may want to use a lot peat moss or maybe even some sulfur to bring it down,” he says. In terms of the borers, Mike recommends the use of a pheromone disrupting device to interfere with the invasive moth. He also suggests applying Surround clay spray to the bark, which would also keep them off.