Heuchera Care: Stopping the Crown From Lifting Out of the Ground

The one problem that kills established plants

A heuchera does not grow from a spreading root system the way most perennials do. It grows from a short vertical stem, the crown, and every year that stem adds a new tier of leaves on top and abandons the tier below. The abandoned tier leaves behind a ring of woody stub. Do this three or four times and the living rosette is sitting six inches (15 cm) above the soil on a bare, corky column with almost no roots attached to it.

That column is the problem. Roots come out of the base of each year's growth, so the roots on a lifted plant are old, deep and slowly dying, while the part of the stem that could make new roots is up in dry air. The plant looks fine in spring and then collapses in the first hot dry spell, because the working roots are no longer under the working leaves. People usually blame drought or a soil problem. It is neither.

Frost accelerates it. Winter heave lifts the crown further each freeze-thaw cycle, and in cold gardens you will often find plants half out of the ground in late winter with roots showing. Push them back down as a stopgap, but understand that pushing down a woody stump does not make it root. Only cutting the stump off does.

If you only ever do one thing to a heuchera, do this: every third spring, lift it, cut the woody stem back to within an inch (2 cm) of the lowest living leaves, and replant so the base of that leaf tuft sits at soil level. Plants treated this way live indefinitely. Plants left alone rarely last past five years.

How to do the lift-and-replant

Do this as growth restarts, when nights stop freezing hard but before the plant is working at full speed. Autumn works in mild gardens; in cold gardens a plant replanted in autumn has not rooted before the ground starts heaving and gets pushed straight back out.

1. Lift the whole plant Push a fork in a hand's width outside the leaves on all sides and lever the plant up whole. Shake and wash the soil off until you can see the woody stem and where the roots actually come from. You need to see this clearly to cut in the right place.
2. Cut the stump back With a clean knife or pruners, cut straight across the woody stem, leaving one to two inches (2-5 cm) of stem below the lowest living leaves. Cut off the old root mass with it. This feels drastic and is not: the leafy top will make new roots from the cut stem within a few weeks.
3. Tidy the stem Pull off the dry brown leaf bases clinging to the stem so bare tissue is exposed, and cut away any part that is brown or hollow inside. Healthy stem is firm and pale green or cream in cross-section. Brown, crumbly or tunneled tissue means grubs; check the section on pests before replanting.
4. Replant deeper than it was Set the plant back so soil comes right up to the base of the lowest living leaves, with the cut stem entirely buried. Firm it in with your hands and water thoroughly. Do not bury the leaves themselves or the center will rot.
5. Keep it damp for six weeks The plant has no working roots until it makes them. Water whenever the top inch (2-3 cm) of soil is dry, and shade it through hot afternoons if you did the job late. New white roots appear from the buried stem in three to six weeks and it becomes self-sufficient.

Watering, feeding and the rest of the year

Heuchera has a shallow, fibrous root system that occupies only the top six to eight inches (15-20 cm) of soil. That makes it quick to wilt in dry heat and equally quick to rot in soil that stays saturated in winter. Aim for soil that drains but holds some moisture: leaf mold or compost worked into the top spit is the single most useful improvement you can make. On heavy clay, plant on a slight mound instead of in a hollow.

Water established plants only in genuine dry spells, and water the ground rather than the leaves. Plants in containers are a different matter and need checking every day or two in summer, because the small root ball dries out fast and a heuchera that dries to the point of wilting loses its lower leaves permanently.

Feed lightly or not at all. A handful of general fertilizer scattered around each plant as growth restarts is plenty. Rich feeding produces large soft leaves that flop, scorch more easily, and encourage the crown to stack up faster than it otherwise would. Overfed heucheras look magnificent in early summer and tatty by autumn.

Grooming the leaves and what to write down

The foliage is evergreen or semi-evergreen, so the plant carries its old leaves through winter and they matter. Leave them on through cold weather; they protect the crown. Once hard frosts are past, pull off every leaf that is brown, spotted or lying flat on the soil, taking the leaf stalk with it by tugging sideways and downwards rather than cutting. This one tidy-up transforms how the plant looks for the rest of the year and removes the damp litter that harbors pests around the crown.

Through summer, pick off individual leaves as they go brown at the edges rather than waiting for a general clean-up. A heuchera holds a leaf for about a year, so there is always a slow turnover, and removing the old ones keeps the color of the new ones honest.

Keep a short record for each plant: where it is, the amount of sun it actually gets in midsummer, the year you last lifted and replanted it, and how deep the woody neck had become when you did. That last figure tells you your own interval. In light soil with mild winters a plant may go four years; in a cold garden on clay it may need doing every second spring. Noting the date of the lift is what stops you losing a plant you have had for years to a job you meant to get around to.

Also record which plants scorched and which stayed clean, along with their position. Leaf color and sun tolerance vary enormously between plants, and your own notes are far more reliable than a general rule about how much sun heuchera will take.