Gadenin日本語Get the appThe shape of the nandina year
The calendar for this plant is set by two things. The first is the life cycle of the individual canes, which come up from the base, take a few years to reach full height, flower and fruit at the tip, then go woody and bare below. The second is the fruit, which colors in autumn and hangs on all winter, and which is the part of the plant that causes trouble for birds and for wild ground.
Almost everything you do in a year is an intervention in one of those two cycles: taking out old canes so new ones come up, or taking off fruit before it becomes a problem. Together they account for perhaps half an hour of work annually on an established clump.
The third element of the year is inaction. A large amount of what looks like damage on this plant, particularly winter leaf browning, recovers without help and is made worse by cutting. Knowing when not to touch it matters as much as the two jobs that need doing.
Everything below is written by season rather than by month so it reads the same in either hemisphere. Adjust by watching the plant: bud movement, fruit coloring and the first hard frost are more reliable markers than any date.
Season by season
Use this as a checklist rather than a set of appointments. In a mild year everything shifts earlier by two or three weeks and in a cold one later, but the order of the jobs never changes.
| Season | Main job | What to watch for |
|---|---|---|
| Late winter, dormant | Renewal cut: a third of the canes to the ground | Thick gray canes bare for most of their length |
| Late winter, dormant | Staggered cuts on middle-aged canes at half and two thirds height | An empty zone in the middle of the clump |
| Late winter, dormant | Divide the clump or detach outlying suckers | Single canes standing clear of the main body |
| Early spring | Mulch two inches (5 cm) over the root area | Keep the mulch clear of the cane bases |
| Early spring | Treat alkaline soil if new leaves are yellowing | Yellow blades with distinctly green veins on new growth |
| Late spring | Cut out canes that are genuinely dead after winter | Wait until new growth is clearly moving before judging |
| Late spring | Count the new canes coming up at the base | Four or five a year means the clump is in good order |
| Early summer | Nothing beyond watering new plants | Loose white flower sprays opening at the cane tips |
| Midsummer | Deep water only in real drought | Foliage still limp at dawn, not dull in the afternoon |
| Late summer | Take semi-ripe cuttings if you want more plants | Shoots that flex and spring back rather than snapping |
| Autumn | Cut off the fruit clusters | Berries fully colored but still firm, before birds arrive |
| Autumn | Plant, transplant and divide | Soil still warm while the plant slows down |
| Winter | Leave winter leaf browning completely alone | Brown crisp edges on the windward side, canes still alive |
The late winter renewal cut in detail
If you do only one thing for a nandina all year, do this. It is the job that decides whether the plant stays full to the ground or turns into a bundle of bare sticks with a tuft of leaves on top, and it takes ten minutes on an established clump with a pair of hand pruners.
- Count the canes before you cut anything Work out how many canes the clump has in total, and sort them by eye into old, middle-aged and young. A typical established plant has eight to twenty canes across three or four age classes.
- Take a third of them to the ground Cut the oldest, tallest and barest canes off at soil level. Removing a third each year renews the whole clump on a three-year cycle so it never carries a cane old enough to go bare.
- Cut a second group at half and two thirds height Choose middle-aged canes and cut them at staggered heights just above a leaf joint. They break from below the cut and fill the middle of the clump, which is otherwise the part that empties out.
- Leave the remaining canes untouched These carry the height and this year's flowers. Resist the urge to even them up. A clump where every cane is the same length is exactly the flat-topped result the staggered method exists to prevent.
- Clear the inside of the clump Pull out dead canes, old leaf litter, grass and weeds from the base while you have access. Air moving through the middle is worth more than any spray against the leaf spots that appear on congested plants.
- Write down the numbers Note how many canes the clump had, how many you removed, and how many new canes came up the previous spring. Those three figures tell you whether the plant is keeping pace with the renewal cycle.
The count of new canes appearing at the base each spring is the single most useful number to keep for a nandina. A clump producing four or five a year sustains the renewal cycle indefinitely; one producing none is telling you it is short of light or losing out to tree roots, long before the foliage shows it.
Judgement calls that recur every year
The first is the fruit. Berries hold on the canes right through winter and are a large part of the plant's appeal, but they contain cyanogenic compounds and have killed flocking birds that gorge on them, and birds carry the seed into wild ground where the plant has become invasive in parts of the southeastern United States. Removing the clusters in autumn takes five minutes and settles both. Where the plant is locally listed as invasive, treat removal as required rather than optional.
The second is winter damage. Every year an exposed plant browns at the leaf edges and looks finished, and every year most of it recovers once soil temperatures rise. Cutting in late winter, while it still looks dead, removes living wood and exposes fresh tissue to more of the same weather. Wait until late spring, then cut only what is genuinely dead.
The third is knowing when to stop. A clump that is throwing up new canes at the base, holding foliage down its full height and coloring in autumn needs nothing beyond the mulch and the annual renewal cut. Extra feeding, extra watering and any kind of shearing all make an established nandina worse rather than better.