The increase in temperatures and longer daylight hours means that our orchids are growing quickly. However, sudden changes to their environment, such as high temperatures, can cause stress to an orchid. Just like us humans, our orchids can become overheated or develop sunburn in the summer months if we do not provide the appropriate care.
There are some things you can do to help, particularly during a mini-heatwave, as we seem to be experiencing at the moment (weird!). The main things to keep an eye out for in the summer are:
- Dehydration. Your orchid will be using more water to help fuel its growth in the lighter days, and so can dry out much faster than in winter. Ensure your orchid has the enough water each week to keep it hydrated and healthy. I find that increasing the amount of times I mist my orchids also helps.
- Sun burn. Whilst there are some orchids that can tolerate direct sun for short periods of time, others will not. The temperature of the leaves increases rapidly, causing cell collapse and the orchid ends up with scorch marks. To avoid this, do not place your orchids in direct sun unless you know they can handle it. Sometimes heat tolerant orchids can become scorched if their leaves are touching windows for any length of time. You could put shade netting up at windows to help reduce the light levels.
- Heat stress. Most plants generally can adapt quickly to their surroundings – orchids take more time. Heat stress is the equivalent of heat stroke for us. To put it simply, the orchid cannot produce enough proteins to help it stop overheating. It may well look a little “off” if it is not helped to cool down quickly. Keeping the temperature of the leaves cool will help by misting them, as will air movement.
- High humidity. If you have high humidity, you also need good ventilation. If there is little or no air movement, moulds and rot can set in surprisingly fast. To keep your orchid healthy, you could open a window slightly or place a fan in the same room to circulate the air. If the temperature gets above 24c in my orchid grow space, our trusty floor fan goes on. This keeps the leaves cooler too, reducing heat stress.
- Pests. If pests are left unchecked, they can cause havoc to your precious plants. In the warmer months, they are far more active and will travel from plant to plant looking for somewhere to lay eggs. Most of them breed in huge numbers and can quickly swamp an orchid. There are various treatments for them, depending on the creepy crawly, but always give your orchids a little attention.
- TLC. I cannot stress this enough; give your orchids your time and you’ll soon pick up on what is working for them and what needs to change.
Most of the time it comes down to common sense, but having a few extra tricks up your sleeve is helpful.