Article and Photos by: Evin Morrison, Extension Master Gardener
We’ve all heard of spring cleaning, but now that nighttime temperatures are dropping into the 40s and lower, we need to think about fall cleaning for our tropical plants. If you’re a houseplant enthusiast, one of the biggest advantages of living in North Virginia is that our summer months boast ideal conditions for growing houseplants outside. However, now that it’s time to bring in and protect these tender plants from winter weather, there are a few things you can do to ensure an easy transition to your home or greenhouse.
When to Move Your Plants
Most houseplants come from more tropical or desert climates, which makes them more suitable to survive indoors than our native perennials. However, it also means they will not do well in temperatures below approximately 50 degrees. Even though the afternoon sun may be shining and we still have warm days, the cold nights will damage tropical species. Keep an eye on the 10-day forecast and once nights are dipping into the low 40s consistently, it’s time to make space for your plants inside.
The Planning Stage
It’s likely your plants put on growth over the summer, so that perfect spot for your monstera last winter might no longer fit its beautiful new growth. Before you start hauling heavy pots back and forth, take the time to measure the space. Rolling plant trays not only will help you move your plants but also will help protect your floors from watering and scratching. It’s better to order and have trays on hand before you start moving plants.
A Little Fall Cleaning
Move all your plants to a flat, clear surface like a patio or deck and use a scrub brush and soapy water to clean off the exterior and the bottoms of your planters. This way you will bring your planters back inside looking their best and you’ll also be scrubbing and rinsing away any hidden pests, spider webs, or insect eggs. Make sure to schedule enough time to let the sun dry out your planters a bit. It’s not fun to haul around wet planters, and freshly watered planters will be pretty heavy.
Pruning and Propagating
While your planters are drying in the sun, look your plants over. It’s a good time to prune off any yellowing or dead leaves. Any declining foliage or branches will most likely decline faster indoors, so trim them away. Only bring strong, healthy plants into your home for the best chance of a successful transition.
Again, there’s a good chance your plants thrived this summer and had a growth spurt. If your plants are now too big for your space, take the time to propagate the new growth. Not only will you be able to fit all your favorite plants back into your home, but if you propagate them now, the cuttings will have time to develop roots before the holiday season. You’ll have a whole pile of gift plants for friends and family. For more info on propagation methods, check out this Virginia Cooperative Extension article.
One of the biggest concerns when moving plants outside and back in is the hidden guests you might bring inside. Luckily, plants that have been outside mostly are much happier and aren’t sending out distress hormones that attract bad pests like spider mites, scale, and mealy bugs. It’s much more likely you’ll find a few hidden spiders or a beetle or two, and sometimes small frogs and lizards can even hitch a ride. Before you bring your plants inside, give every leaf and limb a good inspection.
Use a damp microfiber cloth, like the ones used to clean electronics, and wipe down all the leaves. Rinse the cloth between each swipe. That way, dust, dirt, and pests will be wiped away before they can come inside. Wiping leaves will also set your plants up for success, as dust from your home and newly turned-on heat is a breeding environment for spider mites. It’s a good idea to continue dusting your plant leaves throughout the winter and spring season. You can even put them in the shower occasionally to simulate the rainstorms that kept them clean all summer.
Even after your thorough inspection, though, some sneaky critters might make their way inside. Most of these creatures are harmless and helpful, so please trap them and take them outside.
Lastly, it’s not uncommon for ants to make a nest in the soil of planters or for fungus gnats to have laid eggs while outdoors. Before moving your plants inside, it’s a smart idea to scoop out the top 2 inches of soil or substrate and leave it outdoors. Fungus gnats rarely lay eggs any deeper than 2 inches, so leaving them outside will avoid an infestation. And by disturbing the top layer of soil, you will also disrupt the ants, which will alert you to their presence. If there are ants, unpot the plant, rinse the roots and planters, and repot in fresh substrate.
Tuck Your Plants in for Winter
Mix up a fresh soil mixture to top dress your plants and replace the soil you removed. You can add in worm castings or slow-release fertilizer to feed the roots throughout the winter season. These plants are entering a dormant period, so weekly fertilizing as in the summer won’t be necessary. A little amount of extra nutrients will ensure healthy plants throughout the dreary winter months.
It’s also helpful to “mulch” your planters. Use bagged orchid bark to top off bare soil. The heat in our homes not only dries out our skin but dries out plants, too. Add a one inch layer of orchid bark to help maintain moisture between waterings inside. It gives a nicer look to your plants while they are joining you indoors for winter.