And now a word from Mark Cullen--Tropical Plants

Enjoy Your Indoor Tropical Plants this Winter!

In winter, Canadian gardeners focus on indoor tropical plants. This is fortunate for the plants because this is when they most need our attention. Thanks to central heat, the air in our homes is very dry, creating perfect conditions for insects to thrive. Furthermore, the short winter days are hard on any indoor plant that enjoys sunshine.

How to Help Tropical Plants Weather Winter

The short winter days and extreme temperatures encourage indoor “tropical” plants to slow their growth and many enter a period of dormancy. Because indoor plants are not actively growing during the winter, they do not require fertilizer at this time. In many cases, you should also cut back on watering. Check the soil with your finger: only apply water if the top 2” (5 cm) of soil are dry to the touch. Tropical plants are sensitive to cold draughts and should be kept away from frequently used exterior doors. Window sills are often too cold for them. If foliage rests against a window it may show signs of stress over time. The dry heat of home furnaces reduces interior humidity levels and causes plants to dry out quickly. Signs of low humidity stress include brown leaf tips, yellow leaf edges, dropped flower buds and insect problems. A humidifier will help to maintain healthy humidity levels and allow indoor plants to perform much better through the winter.

Keeping Plants Clean Keeps them Healthy

Outdoor plants are cleaned regularly by rain and wind. Indoor plants need us to do the job. Dirty leaves cannot absorb as much sunlight as clean ones, which affects the overall health of the plant. Use Green Earth^® plant shine or Green Earth insecticidal soap to improve plant appearance, stimulate growth and help to control insect pests. Moisten a sponge or fabric with the plant shine or insecticidal soap. Support the leaf with one hand and gently wipe the top and bottom of the leaf with the cloth. Keep in mind that most insect problems occur on the bottom side of leaves. Plants with hairy leaves, like African Violets, should not be cleaned with a damp cloth. Use a soft cosmetic brush to dust the leaves.

I give my tropical plants a full shower in the winter. I move them into the bath tub and gently but thoroughly shower the leaves, taking care to make contact with the underside of the leaves.

This is also a great time to “purge” potting soil of insoluble salts. If you have a white or chalk-like deposit on the bottom of the pot or on the surface of the soil, you can cleanse the soil using the laundry tub faucet or your shower to thoroughly soak the soil to flush out toxic salts. Keep soaking the soil until water runs freely from the drainage holes on the bottom of the container. (Put a filter over the drain of your sink to avoid plumbing problems!)

While we may have a long winter ahead of us, there is no reason for gardeners to miss out on their favourite hobby. Not only do tropical plants provide plenty of oxygen and natural humidity, tending them offers a welcome respite from the outdoor temperature and is a reminder of warmer days to come.

How Do You Know When Your Indoor Plants Need Repotting?

You may be tempted to repot houseplants while you are showering them with attention, but I recommend that you do this just before they enter the growing season in February or March. When roots begin to grow out of the bottom of the pot and show themselves at the surface of the soil, it is time to repot into a clean container with a drainage hole, using quality potting mix.

Choose a pot one size larger than the existing container. Water the plant several hours prior to repotting. Support the base of the plant with one hand and turn over the container. Gently pull the pot from the base of the plant. If the roots are circled around the root ball, use a sharp knife to cut into the roots. Make evenly spaced vertical cuts, 2 cm deep, from the top of the root mass to the bottom. This will encourage new root growth and stop the circling roots. Place a Mark’s Choice^® Pot Hole disc in the base of the new container. This will ensure that the drainage holes are not clogged by soil over time. Fill the pot with enough potting soil so the root mass is 3 cm below the top edge of the pot. Add potting soil to fill in around the roots, tamp the soil in place with a Home Hardware paint stick and water thoroughly to remove air pockets. If air pockets exist in the soil the roots will dry out.