Growing Sundews Outdoors
It seems that a lot of growers have trouble growing sundews outdoors, but it can be much easier if you follow a few guidelines that minimize stress and maximize dew production. Since many variables are out of your control when you bring sundews outdoors, there are several things that can be done to make your sundews as happy as possible. Growing Drosera outside has many benefits, but it also comes with drawbacks. This information can be found at the bottom of this article.Light intensity and Temperature
Light intensity and Temperature go hand-in-hand when growing sundews outdoors. While you have no control over the overall outdoor temperature, you can control the temperature that your sundews reach. To make sure your Drosera don't overheat, you can place your pots in a large tray (or in individual trays) at ground level. The ground is capable of staying slightly cooler than the air temperature. Another way you can reduce the temperature the plants reach is by placing them in a partly sunny or somewhat shaded location. While the sundews may not get as much light as they need, they will be safe from the risk of scorching.
If you want to grow your sundews in a bright location, the safest way of doing this is by gradually acclimating your plants. Acclimation is the steady process of increasing light intensity, temperature, etc. so that the plant has the ability to adjust to the new conditions, and will not go into shock from being moved from the shade into bright light. If you've moved your sundews outdoors into the sun, and they start to burn or turn brown, this is a sign that they are going into shock. To acclimate sundews to bright light, a typical strategy would be to first grow them in a shadier location the first week, move them to a partly sunny location for 2 weeks, and then move them into full sun after that. If you find that your plants are still declining at any point during this acclimation process (such as at the final stage, when the plants are finally in full sun) then it means that conditions may be too extreme for the sundews in that location, and they should be grown in one of the first acclimation locations you grew them in previously. The key is experimentation. For example, my sundews declined in the heat and bright conditions of a full sun location, but they thrived in a partly sunny location.
Humidity
One way I've successfully used to boost the humidity around sundews outdoors is to grow all of your plants in a larger tray or miniature swimming pool. This creates a humid microclimate directly around the sundews, so that they will be able to "hold on" to their dew even during the hottest parts of the day. If your sundews are subjected to elevated temperatures, or are grown in a sunny location, this increases water loss (due to higher transpiration rates). To compensate for this stress, Drosera reduce the amount of water loss by reducing the opening of their stomates and water channel concentrations, so that the least amount of water will be lost during this time. Boosting the humidity around the plants reduces this stress and allows the plants to continue to produce dew even during the brightest, warmest parts of the day (considering the light intensity, temperature, and air movement are not extreme). Growing sundews near the ground, or beside a building will reduce air movement, which tends to carry away dew (since it also is responsible for increasing transpiration rates).
Benefits of Outdoor Sundew Growing
- No electricity is needed for lighting, humidifiers, or fans.
- Sundews catch plenty of insects on their own outdoors, so they won't have to be fed by hand (which can take a ton of time if you have a large collection).
- You won't have to worry about family members complaining that your sundews are taking up too much space in the house :)
Drawbacks to Growing Sundews Outdoors
- Birds, chipmunks, squirrels, and other creatures seem to enjoy digging through the peat and long-fibered sphagnum. There was one ground squirrel that buried around 30 sunflower seeds from a bird feeder nearby in one of my pots of D. capensis. Once they sprouted, they pushed up many of the plants, and they died. A squirrel buried some acorns in one of my D. binata pots and dug up/killed many plants in the process.
- There is limited control over humidity, temperature, and air movement. If you live in a temperate environment with very cold winters, you will have to grow most of your sundews indoors during the frigid months. This usually involves pouring a lot of insecticides (or Neem oil) into the soil before bringing the sundews indoors, since many insects tend to accumulate in the pots when growing outdoors.
Combatting Outdooor Growing Issues
- Chicken wire has done an excellent job of preventing rodents and birds from damaging my sundews. The only downside is that it looks somewhat tacky and takes away from the beauty of the sundews inside of it. Unfortunately, chicken wire is a "must have" for me whenever I grow sundews in my backyard. Some growers are lucky and don't seem to have this problem, so this may not be necessary for everyone.
- Use the tray method outdoors to boost humidity and ensure that your pots don't dry out. Here's a picture of my outdoor tray, using a sandbox I purchased at a garage sale:
Many Nepenthes can even do well on the tray method outdoors if a tall enough pot is used, considering they are placed in an appropriate location (without a combination of intense sun and heat)..
Additional Questions or Suggestions?
Contact me at: sundewman(at)yahoo.com