Dividing Sarracenia: splitting a crowded pitcher plant clump

Why Sarracenia need dividing

A healthy pitcher plant clump keeps spreading outward. The ICPS division page explains that Sarracenia like to grow into open soil, so the best pitchers come from the edge of the clump, while in the middle the rhizomes grow over one another and the growth weakens. Its advice is to divide well-cared-for plants about every three years, including plants in an outdoor bog ^[1]. The ICPS Sarracenia guide puts the interval at every 3 or 4 years for well-grown plants ^[2]. A pot that has started to deform, or a rhizome that has hit the rim and turned downward as in the ICPS example, is a clear sign ^[1].

Division is also the standard way to multiply a particular plant, such as a favorite clone of Sarracenia flava, because every piece is genetically the same as the parent. Barry Rice wrote in 2004 that all vegetative methods then in use relied on dividing the rhizome ^[4].

When to divide

The sources give two answers, and they suit different climates.

The division page calls early spring the only good time, while the rhizome rot page, written to reduce infection, prefers fall division where winters are mild. Where frosts are hard, both point to the end of winter.

What you need

• A place where you can make a mess; the ICPS author works on a plastic sheet laid over a patio ^[1].
• A bucket of soil. The division page uses a 50:50 mix of peat moss and perlite, or coarse sand instead of perlite ^[1]. The ICPS growing guide treats 1:1 peat:sand as the default and allows perlite in place of sand mainly for outdoor plants that are flushed by plenty of water ^[2]. More detail is in soil.
• Pruning shears or a knife, and plastic gloves ^[1].
• Weed-block cloth for the pot bottom, plant tags and a soft pencil ^[1].

Step by step

1. Grip the leaves and pull the plant out of its pot ^[1].
2. If you are reusing the pot, line the bottom with a piece of weed-block cloth so the soil does not wash out ^[1].
3. Let the plant show you where to split it. Take hold of a large section of the clump and rock it back and forth to find a place where the old rhizome is thin or weak. Try all the way around before committing ^[1].
4. Aim for at least three growth points on each piece. The ICPS page says three-point divisions recover much better and give good pitchers in the first year, while single-point divisions struggle for the first year or two ^[1].
5. Go back to the main clump and repeat, looking for weak spots behind the newer growth. If rocking does not work, move on to cleaning ^[1].
6. Peel the old leaves off each piece. Leave any that resist, but make sure every old brown leaf is gone: the thatch at the base is a breeding ground for mealybugs ^[1].
7. Lay the pieces out and check them for soft spots on the rhizome and for pests ^[1].
8. On very vigorous plants, cut the remaining joins with pruning shears or a large knife. It is easier to see where to cut once the plant is clean ^[1].
9. Trim back the leaves ^[1].
10. Fill the pot halfway with soil, set the plant at the height you want it to end up, and water. Then fill the pot, water again, adjust the height and position, and add a tag ^[1].

Extra divisions can go into a larger display pot; the ICPS page notes that a big pot is easier for a new owner to look after ^[1]. The old soil can be reused or put on the garden ^[1].

Cleaning the rhizome is rot prevention

Steps 6 and 7 matter more than they look. The ICPS rhizome rot page explains that old Sarracenia rhizomes carry dead tissue, both dead rhizome sections and old leaf bases. Under low-nutrient conditions it stays harmless, but fertilizer lets weak pathogens such as Rhizoctonia and Fusarium feed on the dead material and then attack living tissue ^[3]. Its advice for repotting is to pull dead leaves off rather than clip them, and to cut back dead rhizome ends until no brown remains, even a small brown spot surrounded by healthy tissue. The plant may end up smaller, which the page considers better than losing it ^[3]. Mature plants should not be given soil fertilizer ^[2].

The same cleaning helps with pests. The ICPS mealybug page says these insects favor the crevices where leaves join the crown, usually arrive on plants from other growers, and should be checked for when new plants are quarantined, with a second look a few weeks later ^[5]. That applies to divisions you swap with friends. See rhizome and root rot and aphids, mealybugs and scale.

Small divisions and single growth points

One- and two-point pieces happen in almost every division ^[1]. Rice notes that a rhizome piece without a growing tip often still succeeds, because a dormant lateral node along the rhizome usually wakes up and produces leaves, which may be small and distorted at first ^[4].

Tobias Isenberg described a deliberate case in CPN. His potted S. flava had a rhizome about 12 cm long with only one growing point, so he cut it into two pieces of about 6 cm, one with the tip and one with only roots. The tipless piece stayed firm but showed nothing for months; in October a small leaf appeared, followed by two more growth points, and by November its largest pitcher was about 12 cm long. That summer the mother plant made pitchers of about 30 cm instead of its usual 50 cm, which he put down to the shock of division ^[6]. It is one plant, not a trial, but it shows what to expect from a piece with no visible bud: a long wait, then small growth.

Aftercare

Return the pots to their water tray. The ICPS guide keeps potted Sarracenia in about 4 to 6 cm of water, never lets them dry out, and recommends pots 16 to 20 cm wide for mature specimens ^[2]. The ICPS step-by-step page ends with a photo of its repotted plant five months after division ^[1]. Neither ICPS page publishes a failure rate for divisions.

Leaf pullings for S. purpurea and S. psittacina

Barry Rice tested a method that needs no rhizome cutting at all ^[4]:

1. Pull a whole leaf off the rhizome so that its clasping base comes with it. Do not cut it off, and do not slice off rhizome tissue with it, which could open the rhizome to infection. Leaves that snap at the narrow point above the base are of no use, a problem he found especially common in S. psittacina.
2. Insert the base about 3 cm deep for the low-growing species and about 5 cm for upright ones. Dead long-fiber sphagnum gave his best results; a 50:50 sand:peat mix also worked.
3. Keep the pot in a sealed bag with a little standing water until new leaves appear. The pitcher itself slowly dies back from the tip, but the pulling is still alive as long as its base does not brown and rot.

In his trials, roots formed within about a month and leaves a month or two after that. With about five pullings per species, he reported nearly 100% success for S. purpurea and S. psittacina but only about 20% for the other species he tried; S. leucophylla and S. oreophila pullings had rooted but not yet made leaves when he wrote ^[4]. All his pullings were made in spring, and he suggested the method may prove reliable only for those two low-growing species, which rarely divide on their own in cultivation ^[4]. For raising new genetic combinations rather than clones, see sowing seeds and cold stratification.