If you’re chomping at the bit to get out in the garden, you can satisfy your craving somewhat by giving your houseplants a little TLC. This is a great time of year to trim, repot, propagate and divide houseplants. It’s also a great time to check up on any special garden plants you overwintered in the house or garage.
Some of my houseplants get a little leggy indoors. No matter how bad they may look midwinter, I resist the urge to cut them back until the brighter spring sunshine returns. Most houseplants’ growth slows or stops altogether during the winter months anyway. Pruning and trimming houseplants encourages new growth, and doing so during the dimly lit winter months does nothing but encourage weak, spindly growth.
No matter what time of year it is, it’s always a good idea to remove dead and dying foliage from houseplants. Somewhere I read that a “yellowed leaf never turns green again”. This is a great rule of thumb. Sometimes leaves that look a bit pale can be revved up with a dose of fertilizer, but once a leaf has turned yellow, it is a goner.
Spring is the perfect time of year to repot plants that need larger living quarters. When repotting, choose pots that are only an inch or two bigger than the existing pot. If you use a pot that is dramatically larger, you end up with a large volume of soil that doesn’t contain roots. When watered, this large soil volume stays wet for extended periods because there are no roots there to take up the available water. This may encourage root rots.
Use a high-quality soilless mix which drains well for repotting. Soilless mix consists of an organic component, typically peat moss or bark, plus a mineral component such as vermiculite, perlite, and/or sand. These mixes are lightweight and allow for good drainage and healthy root growth. Mixes containing soil are typically too heavy and retain too much moisture in pots, contributing to root rots.
My personal experience with inexpensive potting soil resulted in the demise of my amaryllis collection I had amassed during college. As a poor starving graduate student I repotted my bulbs using a "potting soil" that was on sale, and it drained very poorly. The excess moisture around the bulbs resulted in them rapidly deteriorating and rotting. Needless to say, I learned my lesson and have never purchased that type of potting mix again.
As new growth begins in the spring, it is the perfect time to propagate many houseplants. Dividing or taking cuttings are common ways to propagate houseplants. University of Missouri has one of my favorite articles on houseplant propagation with a handy chart of the best method to propagate a long list of common houseplants (https://extension2.missouri.edu/g6560).
If you have taken the time to overwinter tender bulbs or tropical plants this winter, now is the time to assess whether your efforts were successful. Tender bulbs should be firm, not shriveled or mushy, and dormant, or semi-dormant plants should be showing signs of life.
Most every houseplant will benefit from a summer “vacation” spent outdoors. Plants that are considered "high light" lovers will do well in full sun outdoors, and those requiring "medium" or "low light" will usually prefer a shaded location.
But before you rush to move your plants outdoors on that first warm sunny day, keep in mind that the average frost-free date for central Illinois is May 15th (around Mother’s Day is another handy way to remember this date).
Also, remember that plants moved to a sunny patio after a dim winter indoors may suffer sunburned leaves. The "textbook" guideline is to move plants outside gradually starting with a short time each day, building up to being outside 24/7. Personally, I don't have the time nor the patience to move all my plants in and out every day. Every year I end up putting everything outside at once, and I deal with a few sunburned leaves—and if I’m not careful I end up sunburned as well.