Use insect netting to deter pests in the vegetable garden
Covering plants is key in areas of heavy infestation, writes Helen Chesnut.
Q In the past few years, after many years tending the same garden, a new pest has appeared in my chard, spinach and beet plantings The leaves develop discoloured patches and trails. I believe the pest is leaf miner. I try to remove the ruined leaves when I see them, but more always appear. Is there a way to successfully control this insect pest?
A Picking off individual leaves and destroying them works as a control only where leaf miner populations are light. In areas where the insects are in significant numbers, covering the plantings with insect netting or floating row covers is the only sure way to maintain clean leaves.
Growing vegetables that need covering against insect pests in the same bed simplifies the covering. I grow beets and carrots (otherwise marred by carrot rust fly larvae) together in a 120-cm wide bed for easy covering. Lightweight floating row covers designed for use as insect barriers need no support structures. They lift up atop the plants as they grow, “floating” over the planting. Insect netting is more substantial and needs supporting hoops or some other structure to hold it above the plants.
Over a growing season there are several generations of beet and spinach leaf miners. The adults, tiny grey flies, lay eggs on the undersides of leaves. The eggs hatch into larvae that tunnel in between upper and lower leaf surfaces and feed there, creating discoloured blotches and tunnelling.
Plantings can develop in perfect condition for years before insect pests discover and infest them. I grew bulb onions with success without any protective measures for 25 years before a season came when onion flies discovered the planting and their larvae ruined every bulb.
Q Can the hibiscus used to make the bright red tea I like to drink be grown in home gardens?
A Yes. You will find the seeds with photos and planting instructions on the Renee's Garden site (reneesgarden.com) with the herbs. The species used for tea is Hibiscus sabdariffa.