This column is being reproduced with the permission of Steve Smith, The Whistling Gardener, and owner of Sunnyside Nursery in Marysville.
A lot of gardeners wisely move some of their houseplants outside during the summer to give them better light and fresher air. It is a tricky thing to do because light conditions inside our homes are always much more reduced than even the shadiest location in our gardens.
Leaves that have been grown inside our homes have thinner cuticles and are consequently more susceptible to sunburn when moved outside. By taking special care to acclimate them, by first placing them in full shade and gradually moving them into sunnier places in the garden, we can usually be successful.
That being said, now it is time to reverse this ordeal and bring those little friends back inside and try to keep them happy for the rest of the winter. Here are a few things to consider in this process:
Before bringing any plant back into the house, hose it off and do a thorough inspection for bugs and diseases. Check the leaves (both on top and underneath) and the stems as well for aphids, scale, spider mites, mildew, and/or mealy bugs.
Check the soil surface and the drainage hole for hiding critters, like slugs. You can either remove the plant from the container or submerge it in water for 10 minutes, which should drive out any freeloaders.
If you find any pests or diseases, treat them with an insecticide that is labeled for indoor use. If the infestation is severe, it is usually best to part company and start fresh. For plants that you just can’t part with, you might have to wash all the soil off the roots and repot them - which should actually give them a new lease on life.
Because our homes are relatively darker than outside, you should expect to see some leaf drop after a week or two. The plants are merely readjusting to their new environment.
The other big difference between inside and outside is humidity levels. The air in our homes will always be drier, and this too can cause leaf drop. By grouping plants together, and/or placing them on trays full of gravel and water, you can increase the humidity immediately around them.
Misting the foliage is somewhat beneficial as well and will also help keep the foliage clean. Plants can get just as dusty as all those knick-knacks in your house and the dust will interfere with their ability to breathe, so keep them clean.
If possible, separate your returnees from the rest of the flock for a week or two just to make sure they are pest free.
Cut back on the watering. Plants recently returned to the home environment will slow their growth down and use less food and water, so only water when the top one inch of the soil is dry. Always apply enough water to wet the entire soil area, which usually means making sure that you have a fair amount of water coming out the drain hole.
I think it is important to remember that all houseplants are native to some other environment and keeping them cooped up inside can be a challenge. By manipulating the light, water, feed, and humidity, we can usually keep them happy - but don’t get discouraged if you have a few croak on you now and then.
Making them feel like they are part of the family, talking to them and telling them you love them, playing soothing music and keeping them company will all go a long way to being successful. In many ways, they are no different than us. Stay safe and keep on gardening (even if it’s only indoors this time of year).
Sunnyside’s next free class will be "Essential Evergreens" on Saturday, October 24th, 2020, at 10:00 am. For more information or to sign up, visit www.sunnysidenursery.net/classes.
Steve Smith is the owner of Sunnyside Nursery in Marysville, WA, and can be reached at firstname.lastname@example.org.
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