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Although they’re called “houseplants,” we seem to forget that these are living beings that evolved over the millennia outdoors! Plants are not meant to be inside, so this post is focused on when to put plants outside in Spring, and how to do it. Hardening off plants is a very important concept, otherwise you can quickly injure your plants. Keep reading and let me teach you the proper way to do it!
This post will teach you when to put plants outside in the spring and how to harden off your plants. Whether you are moving your vegetable or flower seedlings that you grew indoors, or you are just moving your houseplants, the process is the same.
It is funny because many people have asked me in the past if houseplants can go outside. The “indoors” wasn’t even a thing until very recent times in the history of our Earth! So the short answer is YES they can go outside!
Some people are scared of pests, but to me, the benefits far outweigh the risks. There are steps you can take to prevent and deal with pests when bringing plants back indoors. So be sure to check out my blog post on that topic where I interviewed an expert!
That being said, I would wither up and die if I couldn’t be surrounded by houseplants in my home and office, but we need to keep in mind that nature does a better job than people ever could.
When houseplants are indoors, we will be the most successful if we keep in mind how the particular plant would grow in nature.
However, the absolute best thing that you could do for your houseplants is to move your houseplants outside for the summer.
Why Your Houseplant Will Thrive Outside
There are so many reasons that your houseplants will thrive outdoors:
Rainwater is almost always preferable over tap water. Some plants are sensitive to the additives in tap water. Also, rainwater seems to perform miracles because it contains nitrogen in the form that plants can use, and your houseplant will respond enthusiastically.
Rain also will wash away any dust that has accumulated on the leaves while indoors. It’s like giving yourself a facial and washing all the schmutz off your face. Except it’s not just for the looks. Plants will be able to photosynthesize more efficiently if their leaves are clean.
The humidity and air circulation outdoors will give your tropicals what they need to thrive. The air circulation and wind will make the plants sturdier and stronger. Indoor, stale, bone dry air resulting from forced air heating systems wrecks havoc on our poor houseplants.
The brighter light outdoors will greatly benefit your plant’s growth, although you have to be very careful when you first acclimate your plants to the outdoors. I will teach you how to do this so keep reading.
Often times, plants that have never done much for you indoors will take off and grow luxuriantly after a few months outdoors.
The Alocasia below slowly was languishing indoors in our sunroom. They just seem to detest the indoors for long periods of time. The light indoors wasn’t the issue, but humidity was.
These plants love high humidity, and unless you have a greenhouse, it is difficult to achieve the conditions that it needs. So last summer, I placed this plant outdoors in the shade, and it thrived. It continually threw out leaf after leaf, and each one was bigger than the prior one.
Notice how much bigger the leaf in the upper left hand corner is from the other 2 leaves in the picture. Not only that, this plant actually bloomed for me over the following winter. (The blooms weren’t anything spectacular, but an achievement nonetheless!)
I love to summer my orchids outdoors as well. Often times, orchids that have never flowered will suddenly flower for you. I had one orchid burst out with 4 flowers outdoors and it never put on such a display indoors.
Moth orchids and Christmas cactus, among some others, will benefit from being outdoors because a drop in night time temperature will help trigger blooming.
Take a look at the other plant below. This is my cast iron plant (Aspidistra)
This plant has a fascinating story. My family is from a town called Petrella Tifernina in Italy. My grandmother, before she came to this country, made a division of a cast iron plant from her town’s church and she brought it over to the U.S.A. in 1968. She grew the plant for decades.
When I bought my first house, my grandmother made me a division of her plant, so here it is pictured above. This is an amazing low-light plant that tolerates a lot of neglect. Of course, if you’re kind to it, it’ll look prettier.
I decided to take this plant outdoors last summer and it threw out a few leaves, many more than it used to during a normal growing season! In addition, the leaves were bigger than normal. Nature knows what to do, so let her do the work for you!
Hardening Off Plants
Unfortunately, it’s not as simple as just moving your houseplants outside. Almost, but not quite. There are a couple things that you need to remember when you move your houseplants outside:
Tropical plants just don’t do cold weather. Some of them are surprisingly tolerant though. As a general rule, wait until the nighttime temperatures are at consistently a minimum of 50F (10C).
I like to push the limits sometimes, but if you do so, monitor your plant closely. Look for signs of stress. For example, I couldn’t resist a great price on a hibiscus plant that I saw at Costco recently, so I purchased it. I knew it was too early, but I couldn’t resist. I noticed that night time temperatures in the 40F-45F range was much too cold for these plants.
The leaves were looking a little droopy. To compensate, I moved the plant into the garage each evening until the nights were warm enough to grow in its permanent location outdoors.
On the other hand, I also purchased two huge Boston ferns and they seem to be perfectly fine to have a few cooler nights.
Push the limits and experiment, but keep a close eye on them for signs of stress. If you’re in doubt, stick with my original recommendation of minimum night time temperatures of at least 50F.
When you move your plants outdoors, do NOT put them in the sun at least initially. EVEN IF THEY ARE PLANTS THAT NEED DIRECT SUN! Even if your plant grew in a sunny window indoors, the intensity of the light outdoors is much greater.
Your plant will need a period of hardening off before you can place it into full sun, if your particular plant likes to be in full sun.
So when you take your plant outside, place your plant in COMPLETE shade and let it stay there for a few days before changing location and gradually to more light if needed. If you don’t harden your plant off, the leaves will quickly burn.
Try and place your houseplants in a sheltered area outdoors in an area that is protected from the wind. I’ve had many plants blown over and have had the pots broken or plants themselves damaged.
Houseplant Care Outdoors
Your houseplant will probably require more frequent watering outdoors. Warmer temperatures and air circulation will dry out the soil much more quickly.
Make sure you fertilize your plants in the summer because they will be rapidly growing.
You may want to repot your plant when you move it outside. It’s so much easier to perform this task outdoors. Remember that in nature, the soil is constantly replenishing itself with organic matter, so give your plant extra care and repot it every so often, or at least top dress with fresh soil.
I move as many of my houseplants that I can outside. Of course, I leave a few indoors so that the house doesn’t look barren, but your plants will thank and reward you after a nice long summer outdoors!