What to Feed Venus Fly Traps Indoor
Venus flytrap (Dionaea muscipula)
Venus flytrap is a native of the Carolina coastal plain where it has become very endangered. Fortunately, the plants we purchase for our homes are grown commercially and do not affect the native populations. They grow best as a houseplant in our area (USDA zone 7 and colder). Care is unusual and can be a challenge. The key to a healthy Venus flytrap is strong light, pure water and plenty of food. This plant does not need to enter dormancy when grown indoors, though it can be grown with a dormancy period in the winter that may benefit the plant. Other unusual conditions of growth include a sensitivity to the composition of the growing medium, a need for live food (or simulated live food) and an intolerance of most tap water.
You do not need to remove your plant from the small covered container in which you bought it. Just take off the protective plastic cover. If you do want to re-pot your plant use care to follow its requirements in the Re-potting section below.
Light:
Offering this plant enough light is a big challenge in its care. Strong direct light is crucial to maintaining a healthy plant. Full, direct sunlight (at least 6 hours per day), from a southern exposure is best and most owners will need to consider supplementing with artificial light, especially in the low light months of winter. If your plant is small, a single horticultural LED light may be all you need, kept on the plant for 12 to 16 hours per day. Without the right light it will deteriorate quickly.
If you elect to grow your plant with a dormancy period in winter, light requirements will differ. Be sure to read Winter Dormancy below.
Water and Humidity:
Your Venus flytrap has water requirements that are probably unfamiliar. This plant needs to be kept in potting medium that is like its wetland native habitat, always moist but never soggy. That requires the correct planting medium (see Re-potting, below), a container with a hole in its bottom and a dish of about ½ to 1 inch deep water sitting under the pot.
When you water your plant, do it by adding the water to the dish under the pot and letting the water seep up into the pot. There should always be at least a 2 inch margin between the top of the water level in the dish and the top of the soil level in the pot. Never let the dish of water dry out. If you elect to grow your plant with a dormancy period in winter, care requirements will differ. Be sure to read Winter Dormancy below.
Dionaea muscipula is very sensitive to the type of water you use to care for it. Use distilled water, rainwater or reverse-osmosis water. Tap water and even bottled or filtered water will probably have too much dissolved salt for the plant and can kill it.
Need for added humidity is very specific to your home growing environment. Often, no additional misting is needed as long as you are careful with water. The moist growing environment will create some very localized humidity for the plant. If the dryness of your home, particularly in winter, causes the water dish to dry too rapidly, you can keep your plant in a terrarium-like setting. A terrarium with adjustable ventilation works best or the added heat build up in the summer may cause your plant to wilt.
Temperature:
Normal home temperatures in the 65 to 75ºF. range are appropriate. Protect this plant from challenging micro-climates by keeping it away from heat and air conditioning vents and drafty doors and windows. If it gets cold in your home, the plant will slow its growth and eventually become dormant. See Winter Dormancy below for temperature adjustments if your plant will be grown with a winter dormancy period.
Re-potting:
Do not re-pot a new plant; it should be fine in the container and growing medium in which it was purchased for two years or more. The pot for a small plant is usually about 2 to 3 inches wide and 3 to 4 inches tall.
Your Dionaea is fast-growing. It can use up its space in a container after a year or two and will need to be re-potted. When you notice that the plant has filled the entire container or new traps are failing to develop, it is time to re-pot. You can divide the plant at the same time if you wish. Spring is best. If you have a slower growing plant, it should still be re-potted every two years so that the growing medium is refreshed.
Use a pot with a hole(s) in the bottom and tall enough to keep the planting soil surface a minimum of two inches above the water line in the dish. (Four inches tall is usually sufficient.) The right potting medium will help your Venus' fly trap live a longer life. It should be half, good-quality (horticultural), sphagnum peat or peat moss and half coarse, horticultural sand. The wrong type of peat can have too much mineral content and the wrong sand may have mineral and clumping problems. You can add ½ inch of the sand on the top so that only the roots and bottom of the bulb are in the potting mix. The sand layer will keep most of the plant out of contact with moisture to reduce the chance of rotting and discourage fungus gnats from making themselves at home.
Feeding:
You should not fertilize the soil of your Venus flytrap. The soil of its natural habitat is low in nutrients and fertilizers will slowly kill your plant.
Because of this low nutrient environment, the Venus flytrap has adapted to an unusual feeding strategy. The traps on your plant are modified leaves and should be fed regularly (about once a week to two weeks). Plants can survive for extended periods without being fed but they will grow more slowly. If your plant is being kept outdoors in the summer, it should be fine catching prey on its own. Do not feed your Venus' fly trap meat! Live prey, such as flies, spiders, crickets and slugs are a Venus' fly trap's favorite food. Live meal worms or crickets purchased from the pet store are a great option. Ants may not have enough nutritional value and sometimes come into contact with toxic substances as they scour your home. Caterpillars are not a good choice as some can eat their way back out of the trap.
Do not give a trap any food that is bigger than about 1/3 the size of the trap; larger insects take too long to digest and can cause bacterial rot that kills the trap. It responds to the movement of an insect to avoid wasting energy on consuming non-food sources. When the insect is placed in the trap, the insect's movement will stimulate the trap into the digestion phase, sealing itself for the process. The plant's trap may stay closed for a week or so while digesting its dinner.
You don't need to feed each trap on a plant every time you feed, just one or two. It is fine to feed the same traps repeatedly. They will eventually die after repeated digestion but that is natural. New ones will replace the old!
Feeding your Venus flytrap dried blood worms: You can buy dried blood worms for your plant from your local pet store. Reconstituted dried worms, available as a fish food, are a reliable and easy to obtain food for your plant. Check the label on the product to make sure there are no other additives. Add a few drops of water to some dried blood worms so that they get soft and meaty, then squeeze out before giving a blob about ⅓ of the size of the trap. Massage the trap gently so the plant thinks that the feed is alive. The International Carnivorous Plant Society has a great fact sheet linked in the side column with photos about feeding blood worms to a Venus flytrap and information on how to get your trap to fully seal and digest its food.
Winter Dormancy:
There are differences of opinion regarding whether winter dormancy is necessary among Venus flytrap experts. In their native habitat, these plants do become dormant in the winter and it is a natural way for the plant to rest and restore itself. If you have trouble offering the plant the light it needs to continue healthy growth in winter or if your plant seems as though it could use a rest, you may want to give it a winter of dormancy.
Dormancy will occur naturally as the hours of sunlight diminish in the winter and temperatures get cooler. Around November, your plant's leaves will begin to die back unless you supplement your plant's natural light with grow lights and keep it warm. To give your plant a period of dormancy, allow the light to dwindle naturally and gradually reduce temperature to about 45 to 50 degrees, stop feeding and limit water to keep the growing medium just barely moist so that the plant can take a rest. You can cut off the leaves once they are completely black. It will be ready to resume growth around March and you can ease it back to its usual habitat and routine.
Flowers:
Dionaeagrow tiny white flowers in early spring. It's best to remove them before they bloom, because flowering takes a lot energy from the plant and can reduce the number of leaves being produced.
Things to watch for:
Venus flytrap color will be green in your home, but with bright light, plants can grow more reddish in color. Some Venus' fly traps cultivars are selected to have more naturally red color, like Dionaea 'Red Dragon', D. 'Red Piranha', and D. 'Colin's Red Sunset.' It is that red color, along with a lightly, sweet scent, that helps to attract prey in the wild.
Leaves turn black and die after a few months. No need to worry! On a healthy plant the leaves only last this long and are replaced by new ones. You can cut off the dead leaves when they are completely black.
If your plant becomes sickly, it probably isn't receiving enough sunlight. It needs bright, full sun or supplemental lighting, to make it grow healthy and strong. A gently lit windowsill is too dim for your plant to survive. Consider adding a full-spectrum, horticultural, LED light to supplement the natural sunlight. Other common problems are a build up of salt in the growing medium if distilled water isn't used, root rot if the growing medium is too wet and roots becoming completely dry, even briefly.
The leaves may look different in spring and fall than they do in summer. Your plant may grow more elongated. upright leaves on longer petioles in summer.
Source: https://libguides.nybg.org/c.php?g=654975&p=4597429#:~:text=Live%20prey%2C%20such%20as%20flies,store%20are%20a%20great%20option.