My fascination with houseplants began as a young girl on my family farm. Winter brought many gray days when we were house-bound, and the green plants in my room always provided relief from the barren outdoors.
Through trial and error, I have learned that getting plants to thrive and survive is not really magic. One resource that has helped me is the U of M Extension website. Expert advice and information for outdoor gardening and houseplants is provided free of charge. By accessing this resource, you can limit the frustration of losing your houseplants.
March is the time of year when I start planning the annual migration of my houseplants and tropicals to the outdoors. Every spring my collection of assorted plants moves outdoors for the long awaited dose of fresh air and sunlight. The second migration takes place when I bring my plants back in the house in the fall. I find that the tropical plants grow at a much faster rate outside, and when fall comes around, the adjustment time is slower than in the spring.
Success in the transition of plants to the outdoors lies in three important details: temperature, sunlight and watering.
First, the low temperatures the houseplants are exposed to outdoors are critical to the plants’ health. I manage the moves in the spring and fall based on the least hardy plants. If I protect the least hardy, I will have protected them all. The low temperature I use to dictate a move is 45 degrees based on my plant mix. A good rule of thumb is to wait two to four weeks after the last frost.
Second, the amount of direct sunlight plants are exposed to needs to be monitored. A key factor to the changeover to the outdoors is carefully acclimating the plants to sunlight. Over-sunning too fast can lead to scorching. Carefully expose your plants to a few hours of sunlight and slowly lengthen the exposure time over a few weeks. It can be labor intensive, but in some cases you can take advantage of a shade tree by placing plants under it and moving the plants gradually into more sunny areas.
Third, U of MN Extension research reveals that the principle reason for houseplant fatality is improper watering. Indoor houseplants are often killed by overwatering, but when placed outdoors, they are often killed by underwatering due to more rapid evaporation. You will have to experiment to find the balance of that will work best for your plants.
There are a number of great resources available through the University of Minnesota Extension. One of my favorites is “Ask a Master Gardener,” where Master Gardeners will answer your yard and garden questions by email, in person or over the phone.
Mary Fitch is an Anoka County Extension Master Gardener.