By Vicki Spencer, Master Gardener
People often ask me how I know when to repot my house plants. There are several signs that it is time. Some are obvious, others are more subtle. Some examples include:
• Roots sticking out the bottom of the pot or the plant popping right out of the pot with roots encircling the root ball. These signs indicate the pot is too small for the root system.
• When you water the plant, the water runs right through the pot and spills all over the counter. This means that there is not enough soil to absorb the water.
• The plant doesn’t seem to be growing as quickly as it used to grow. This is an indication that more soil is needed to provide nutrients.
• The plant looks too big in relation to the size of the pot or has become top heavy and tips over easily.
Any one of these signs means that it is time to repot your plant.
When bringing a new plant home from the store or nursery, many people think it should be repotted right away, but it may not be necessary. In fact, it is usually better to wait a few weeks to let the plant get acclimated to the new light, temperature and humidity of your home. That said, there are different opinions about timing.
Some gardeners are strict believers that plants should only be repotted at the beginning of their growth period (usually in the spring). I prefer to repot my plants in late winter, before I can get outdoors to garden, and I always succeed. Regardless of the time of the year, I believe you should repot your plants when they show the signs above. If you don’t, they may die earlier than necessary.
Before repotting, make sure you have some good quality potting soil and a pot that is 1 to 2 inches bigger than the current pot. I always recommend a pot with good drainage holes to prevent root rot.
If you are recycling an old pot, scrub it with warm soapy water or Clorox bleach (one part bleach to nine parts water) and rinse it thoroughly. A clean pot will help prevent the spread of diseases, microorganisms and insect larvae. If you are using a new terra-cotta pot, let it soak for a few hours, because terra-cotta is so dry it can absorb water quickly.
If you are repotting indoors, spread several layers of newspaper over the counter next to your sink, then turn the pot on its side and gently pull the stem to get the plant out of the pot. If the plant is stuck, run a butter knife around the sides of the pot or loosen the soil with a small garden spade. If the roots are tightly bound together, carefully pry them loose and straighten them out with your fingers. Breaking up the root system will help the roots branch out in the new pot. Then prune the roots to stimulate new growth.
Once the plant is ready, fill the new pot about half way with potting soil, depending on the size of the root ball. Place the plant in the center of the pot and fill it with additional soil. While holding the plant stem straight, tamp down the soil with your fingers, paying special attention to the sides. If a stick or small trellis is needed, this is the time to place it in the pot and position it against the plant. Next, add more soil so that it is about 1 inch below the top of the pot. This keeps water from spilling over. Finally, set the pot in the sink and water thoroughly to moisten the soil and settle the potting mix.
Repotting can be stressful to the plant, which is why some people are afraid to do it. We hear stories of plants dying instead of thriving after being repotted. However, if you follow these tips, you should not have a problem:
• Don’t expose the plant to direct sunlight right away.
• Keep the soil evenly moist, not soggy. If the leaves turn limp, it means you need to add water; if the leaves turn yellow, it means you added too much water.
• Use a humidifier if you have one since Colorado’s climate is so dry.
• Never fertilize a newly potted plant or the roots may suffer from fertilizer burn. You should wait about a month before fertilizing a newly potted plant.
Good luck with repotting, and enjoy your house plants while waiting for spring to arrive.