‘Helicopters’ won’t hurt the garden, but they might grow
Question: This year I had tons of helicopter seeds all over my yard and vegetable garden. Was it OK to leave them in the veggie garden, or should I be concerned they will harm my tomatoes and lettuce?
Answer: The helicopters are the winged seeds of maple trees. It has been a bumper crop of seeds this year. Last year’s hot, dry summer stressed many of our trees, resulting in an abundance of seeds produced. The maple seeds won’t harm your vegetables but will sprout into trees, so the seedlings will need to be removed from the garden. This is a daunting task and one you will probably face each year since you have mature maples nearby.
You could try covering the garden with a fine mesh netting or floating row cover to capture the seeds before they reach the ground. Floating row covers are made from a spun material that lets air, light, and water through to the plants growing below. Remove the seed covered netting or row cover once the seeds stop dropping to make cleanup easier.
Q: We planted some Cobalt and Gold St. John's wort over the past couple years. It has not flowered or grown. I read that pruning can help it flower, but my husband wants it to get bigger. I think pruning could also help it get bigger. Is June too late to try and prune it, and how far back should we prune it in June to stimulate flowers and growth?
A: It is not unusual for new plantings to grow very little and not flower the first few years after planting. The plant is channeling most of its energy into forming a robust root system. This is good for the longevity of the plant but frustrating for gardeners looking for bigger flowering plants.
Do minimal pruning at this time. Remove only damaged, rubbing and inward growing branches. The more leaves on the plants, the more energy produced for growing bigger and flowering.
If you decide to fertilize, use a lownitrogen, slow-release fertilizer like Milorganite that promotes balanced above- and belowground growth without further delaying flowering. One application in spring is sufficient. Avoid high-nitrogen, quick-release fertilizers that promote leaf and stem growth, often at the expense of flowers. In the future, prune only if needed, when the plants are dormant since these shrubs form flower buds in the same season they bloom.
Q: I have what appears to be “green onions” popping up in clumps all over my garden. I pulled them out and they have a small white bulb and smell like onions. I didn't plant them. Any ideas?
A: If you are growing chives or alliums (flowering onions), these are likely the source of your onion seedlings. Both are members of the onion family and produce lots of seeds after flowering and populate the garden with seedlings. Removing the flowers as they fade from these plants before they set and drop seeds is a way to enjoy the chives or ornamental alliums and reduce or eliminate unwanted seedlings.