What’s Wrong with my Herbs? A Trouble Shooting Guide
By, Rob Sproule
When the winter winds blow and everything outside, well, dies, a windowsill herb garden becomes a tiny reminder of spring. While growing them indoors is fairly easy, here are a few things to watch out for:
Not Enough Light
Our winters are dark. Very dark. When plunged into darkness, plants’ instinct is to rise above it (literally). Their stems get longer as they stretch upwards, assuming that there is another plant overtop of them that they just need to reach past.
Stretching happens, and expect your indoor herbs to be spindlier than those outdoors. Move them the the sunniest window you have, keeping them 6 inches from the glass to protect from UV rays.
6 hours of sunlight a day is considered minimum for most herbs, but in January we take what we can get. Don’t sweat the stretch; a quick prune in early spring will nip it.
Water Logged Soil
Your plant’s metabolism slows down in the winter, just like yours does. They feel a little less vibrant, get sick easier, and don’t need as much water. If you water them on your summer schedule, you’re likely to waterlog them.
Many of our most popular herbs, like rosemary, oregano, sage and thyme, hail from the Mediterranean where the sun is hot, the soil coarse and the wine amazing. Damp, chilly soil is bad news for them.
Leave your savoury herbs to dry down to sort first knuckle. Leafy herbs, like parsley and chives, are slightly thirstier. Make sure to empty the saucer (I usually water mine in the sink so I can soak them and walk away).
Unfortunately, the signs of overwatering and under watering mimic each other. Yellowing leaves and all around flagging appearance. In the winter, unless you’ve lost your watering can, it’s typically too much water rather than too little.
Edmonton has moderately hard water which, although it’s not as bad as Calgary, some people choose to treat ( http://funkyfluff.ca/water-hardness-in-canada/ ). Treating, or softening your water removes minerals by adding sodium or potassium. It tastes better and doesn’t leave annoying white spots on wine glasses and bath faucets.
Soft water is also terrible for plants. The salts built up quickly, especially in potted plants, and will spell a fairly certain death. Not only that, but you’ll essentially “salt the earth” and make the soil toxic for future plants.
If you treat your water, you’ll need to have a bypass spigot installed for your houseplants (or use rainwater/ melted snow). It’s a pain, but if you want to grow herbs it’s the only way to do it.
Dry Winter Air
Plants thrive with 50% or higher humidity. In our dry winters, and with forced central air, that’s a tall order.
Browning on the tips and then edges of leaves is a dry-air red flag. It’s very common, and not a concern unless the brown starts to spread into the leaf.
Consider keeping a misting bottle near your herbs to give them a shot every day or so (moist leaves also deter bugs like spider mite). Or add a pebble tray underneath (a saucer filled level with small stones that you keep water in and the plant sits on top). Alternatively, you could simply add more plants! Transpiration through leaves increases ambient humidity in the immediate area.
If the browning continues, check for a heat vent nearby. We often forget about them as they blast our tender babies with desiccating dry air.
A host of different bugs can plague your herbs indoors, but thankfully they’re all fairly easy to get rid of. There’s too much information to cover here, so here’s a quick diagnose-and-link for the top 3 pesky buggers:
– Little buggers flying around and living in the soil? Click Here
– Little buggers making webbing on the leaves? Click Here
– Little buggers living on the leaves? Click Here