Use of tulle and drainage material in container


1st question: Is it a good idea to use tulle to cover my greens (kale, swisschard, basil) in containers to prevent pests, ie. whitefly, slugs, etc etc. from infesting the leaves. I was thinking of using clips around edge of container to keep it in place. Do you think this is impractical?
b) I put a layer of newspaper and then about 6 in of pinecones in the base of those containers. I now just read on your website that no materials should be added and can cause more harm. Have I now set myself up for failure with these greens? I assume it is too late to get them out now?
Thank you very much, Marlene


For your first question, tulle is a fine meshed fabric that can drape over your plants. Tulle can be used as a row cover, which is a form of mechanical control against flying pests. Row covers can be supported by hoop structures or laid over the top of plants. Row covers are useful for control of flying pests like the cabbage moths that lay eggs that turn into cabbageworm (caterpillars) that will eat leafy greens, amongst other pests (important for your Swiss chard and kale). You should measure the size of holes in your tulle to ensure they are small enough to prevent the size of flying insect you are trying to prevent. Your row cover should protect against whitefly providing the holes are smaller than 0.35 mm² in size (anything larger than that and whiteflies will be able to get through the holes). You may want to consider typical row cover fabric, which is manufactured from polyester or polypropylene and is a lightweight, gauze-like and non-woven material with smaller ventilation holes. Tulle, or other row covers, will not provide protection against slugs that are hibernating in the soil or slug eggs in the soil. We have handled the slug issue in several queries on our website. Simply type slugs into the Find it Here box located on the right side of our home page to find a number of our archived posts including this one which provides slug prevention advice such as watering early in the morning, keeping a tidy garden, picking slugs off plants late at night when they are active, and using diatomaceous earth as a preventative.


For your second question, the Toronto Master Gardeners Container Gardening Guide provides guidance regarding filler material at the base of containers. This is unnecessary and can contribute to root rot. This holds true for biodegradable materials such as newspaper or pine cones because water does not move easily from finely textured materials to layers of coarser materials. The good news is that as long as your plants have several sets of leaves and a sturdy root system, you can temporarily dig them out while you remove the materials at the bottom of your container and replace with potting soil.