M.T. O'Donnell was joined on the Scotland Grows Show by orchid enthusiast and grower Luke Callaghan, whose passion for orchids began at the age of nine, sparked by a visit to the World Orchid Conference in Glasgow in 1993. Luke's orchid journey is both inspiring and relatable, as he shares his early struggles, admitting he "killed a lot of orchids" before mastering their care. His extensive collection of around 200 specimens makes Luke well placed to give us the top tips we need to help orchids thrive in our homes.
Whether you're caring for a long-time favourite or are hoping to receive one as a Christmas gift, here are Luke’s 10 essential tips to help your orchid thrive indoors this winter.
Orchids are usually sold in clear plastic pots tucked inside ceramic pots. The clear pot isn’t just for show, orchid roots photosynthesise and need light, just like leaves. Remove the decorative ceramic pot and place the clear pot on a saucer so you can keep an eye on the roots and ensure good airflow. Make sure there’s plenty of drainage so water doesn’t collect at the bottom.
Orchids won’t survive in regular potting compost or houseplant soil. Their roots need air just as much as water. A specialist orchid mix containing bark, sphagnum moss, and perlite is ideal as it holds enough moisture to hydrate the plant while allowing the roots to breathe. Repotting every couple of years is a good idea to refresh the mix.
Phalaenopsis orchids need plenty of bright, indirect light to bloom reliably. They do best on a northeast or northwest-facing windowsill where they get consistent daylight without the risk of being scorched by midday sun. Direct sunlight, especially in winter when low-angled rays are more intense, can burn the soft leaves. If you notice red or leathery patches on the foliage, it’s a sign your orchid may be getting too much light.
If your plant is healthy but not flowering, insufficient light is often to blame. Try moving it to a brighter position but always avoid harsh direct sun.
Knowing when to water is just as important as knowing how. Look at the roots inside the clear pot: when they turn silvery white, it’s time to water.
In Scotland, tap water is generally soft and fine for most orchids, but rainwater is even better. Either way, use room temperature water.
Soak the pot thoroughly, allowing water to run right through and out the bottom, then let it drain completely. Never let your orchid sit in water. Standing water is the quickest route to root rot.
Avoid watering on a set schedule, instead, watch the plant. In winter your orchid will likely need water less often, depending on your home’s temperature and humidity.
Overwatering is the most common mistake orchid owners make. “You can almost always bring an orchid back that’s been underwatered,” says Luke, “but it’s very difficult the other way.” Let the roots dry out between waterings, and if in doubt, hold off.
Luke explains that these orchids are epiphytes: they naturally grow on trees and their roots are exposed to air, not constantly soaked. In the wild, they get drenched by tropical rains but then dry out quickly.
Treat orchids like succulents, less is more.
Orchids benefit from regular feeding but only when actively growing. Use a liquid orchid fertiliser at half strength, applying it every second or third watering in spring and summer. During the cooler, darker months, stop feeding altogether. In winter, orchids go into a rest phase and won’t absorb nutrients in the same way. Feeding during this time can lead to salt build-up in the compost, damaging the roots.
Central heating can dry out the air, which isn’t ideal for orchids. To give them a boost, place your orchid pot on a tray filled with pebbles and water, just make sure the pot is raised above the waterline to prevent soggy roots. Grouping orchids or other houseplants together can also create a slightly more humid microclimate.
For the more enthusiastic grower, Luke suggests using a glass cabinet fitted with LED lights to control humidity and temperature, ideal if you're trying to encourage flowering or care for more sensitive types.
Flowering in Phalaenopsis is often triggered by a drop in temperature between day and night. In homes that are uniformly warm, this vital cue can be missing. Try placing your orchid by a cooler window overnight, or in a room that’s a little less heated than the rest of the house.
Luke also recommends giving orchids a summer holiday outdoors in a shady, sheltered spot - a north-facing wall is ideal. The natural light and temperature variation can do wonders for reflowering, but be sure to bring them back indoors before autumn chills set in.
Orchids are surprisingly forgiving. If your plant isn’t flowering, revisit the basics: is it getting enough light, an overnight temperature drop, and correct watering? Don’t expect instant results. As Luke says, “You’re not an orchid grower until you’ve killed a thousand plants.” Every plant is different, and even experienced growers lose a few along the way. The secret is to keep learning and adjusting.
Once the flowers drop, don’t be tempted to bin your orchid. Orchids bloom in cycles: after flowering, they rest, storing energy to bloom again, and that’s normal.
Trim the flower spike back to just above a node (a small bump on the stem), or to the base if the spike turns brown and dries out. Then resume your usual care routine and be patient, it may take a few months for a fresh spike to appear.
You can hear more about Luke’s wonderful orchid collection and his other tips on the Scotland Grows Show, so you can keep your orchids happy through the winter and beyond. Now if a glossy-leaved, flower-laden orchid appears under your Christmas tree this year, you know exactly what to do.