Dividing a crowded Venus flytrap and replanting the pieces

Signs that a flytrap needs dividing

A healthy Venus flytrap grows along its rhizome in one direction while the old end rots away, and it forms side plants that can be split off ^[3]. The ICPS growing guide says that eventually the plant grows across the pot and runs into the side, or the soil becomes so salty that traps on new leaves fail to develop; either way, dividing and repotting renews it ^[1]. The CPN article on indoor flytraps adds roots dying and new traps turning black before they open as signs that something has gone wrong in the old soil ^[2]. Blackening of single old traps is normal; traps turning black explains the difference.

How often depends on how well the plant is fed. The ICPS guide expects a well-kept plant to need repotting about every year, and notes that the more you feed a flytrap, the bigger it gets and the more often it needs repotting ^[1]. The CPN article says every year or two ^[2]. Feeding also drives branching: the ICPS bloodworm page reports that well-fed plants produce many small plants around the base ^[4].

A newly bought plant is the exception. The ICPS checklist advises keeping it in its small pot, which it will not outgrow root-wise, until it has adjusted to your conditions and is growing well. The only reasons it gives for repotting are a more stable root environment or a growth point that has reached the pot edge ^[5].

Timing

Indoor plants grown under lights without dormancy can be divided whenever they need it; the ICPS guide shows plants that have grown under constant lighting for over 10 years and are divided and repotted every year or two ^[1]. Outdoor plants follow the seasons described in dormancy.

Pot, soil and sand

A flytrap has very few roots. The CPN article’s photos of an unpotted plant make the point, and it explains that large pots are about holding water, not about the plant becoming root-bound ^[2]. The ICPS step-by-step page uses taller, wider pots outdoors than indoors, because the plant must sit the right distance above the water it always stands in, a wider pot is harder to knock over, and more soil buffers the roots against temperature swings ^[3].

The height matters because of the water table in the pot. The ICPS guide wants the tray water more than 5 cm (2 in) below the soil surface, a taller pot for wetter soil, and a sandier mix in short pots ^[1]. Do not reuse old soil for flytraps; the CPN article suggests putting it on the garden or using it for outdoor carnivores that are rinsed by rain ^[2]. The soil guide explains the ingredients.

The pure sand on top has several jobs. According to the CPN article, it keeps the older part of the bulb from rotting, stops a mat of moss forming that new growth would have to push through and that could make the soil airless, lets air reach the deeper soil, and does not attract fungus gnats ^[2]. The ICPS guide agrees that plants grown with a centimeter of pure sand on the surface are less likely to lose their older leaves to rot ^[1].

Taking the plant apart

1. Gather planting forceps, a pot of fresh peat and sand mix, coarse sand and a water tray, in a place you can make a mess ^[3].
2. Lift the plant out with the forceps ^[3].
3. Find each growing point. Side plants can be divided off at this stage ^[3]. In the ICPS example of an overgrown ‘Akai Ryu’, the piece kept for replanting had the growth point and enough old leaf bases to give it a good start ^[1].
4. Break off the old part of the rhizome, which rots as the plant grows, and pull off some of the outer leaves around the growing part, outward and downward so each comes away whole. Do not throw these away ^[3]. They are the raw material for Venus flytrap leaf pullings, and the old half of the ‘Akai Ryu’ could be broken into more than a dozen new plants ^[1].

The CPN article describes the same operation as trimming the plant and cutting off the older part of the bulb, which reduces the bulb to a manageable size ^[2].

Replanting each division

1. Reuse the old pot if it is in good condition. Fill it with peat and sand so that the space left at the top equals the length of the white area at the base of the leaves ^[3].
2. Locate the growth point. The plant keeps growing in that direction, so set it slightly off center, aimed toward the middle of the pot ^[3].
3. Make a hole with the forceps, ease the roots in, and settle the plant so the rhizome is just into the soil ^[3].
4. Fill the rest of the pot with pure sand and spray the plant with water, which helps the sand settle ^[3].
5. Put the pot straight into a tray of water so the peat can fully hydrate ^[3].
6. Label the pot ^[3].

The ICPS author’s own preference is roots and the base of the rhizome in peat and sand with the top 1 to 2 cm of pure sand, but the page notes that many growers use the peat and sand mix right to the top with success ^[3]. In the CPN photos, almost the whole plant sits above the peat and sand layer before the sand is added ^[2]. Water with pure water only; see water.

After division

Divisions need the same strong light and regular feeding as any flytrap. The ICPS guide names lots of light and regular meals, such as rehydrated dried bloodworms, among the main requirements ^[1]. Recovery is gradual. On the ICPS step-by-step page, the replanted mother plant is shown again 5 months later looking much better ^[3], and the ICPS guide illustrates its indoor collection with plants that had been divided and repotted 4 to 8 months before the photo ^[1]. No source publishes a failure rate for divisions.

Every division is a clone of its parent, so a named cultivar stays true. Commercial nurseries multiply selected plants by tissue culture instead, and the ICPS notes that nobody grows flytraps from seed commercially except to look for new varieties ^[1]. For the broader repotting routine across genera, see repotting, and for keeping plants growing year-round under lights, see growing indoors.