Hartley Magazine

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Before You Bring Plants into Your Greenhouse

Cooler evenings and shorter days—everything points to summer’s end. It’s time to move plants indoors. Here are a few things to consider before you do.

Realistically assess your indoor space. Whether you plan to begin spring seedlings or grow winter crops, remember to allow room for these activities. Most plants you move in grow larger over the winter, not smaller, so factor this in.

Examine your candidates. To justify the valuable space they’ll occupy, these plants should be of value to you. Are they healthy? Are they likely to stay within bounds for several months? Are they difficult to replace? Of course, winter-blooming plants make a special claim to indoor space.

Check for signs of insects. Some are difficult to detect with the unaided eye, but plants themselves often signal when something is wrong. Are the plant’s leaves unusually pale, puckered or spotted? Aphids–probably the biggest problem in greenhouse settings– are large enough to see, but very clever about locating themselves. Check under leaves, particularly young ones, and at the tips of growing stems; often these tiny insects are colored to match their host plant.

If you find whitefly, it’s probably best to discard the plant. Don’t despair if you locate aphids, however. Try to dislocate the majority with a strong spray of water. Next, apply a spray of horticultural oil or soap– carefully following the manufacturer’s directions. Applying one of these as insurance before you move plants indoors can be a wise idea. If there is an infestation, try to make at least two applications before the move. It’s much easier to control pest problems before plants move inside.

Most plants benefit from occasional pruning. Particularly at this time of year, pruning makes a great deal of sense. Cutting them back makes plants smaller, which helps conserve space. Pruning also reveals insects clustered in the plant’s interior, and then allows easier access for treatment. It generally results in vigorous new growth, increasing the plant’s overall attractiveness too. Don’t prune winter-blooming plants at this time of year, or you might inadvertently remove flower buds.

Investigate what growing conditions are best for the plants you’ve chosen. Many actually prefer cool temperatures with bright light. Isn’t it wonderful that you have a greenhouse!

  • steve

    Can you sreen a greenhouse vent to prevent bugs from getting in?