Gadenin日本語Get the appThe shape of the year
Fish mint has a simple annual cycle: it breaks ground in early spring, grows fast through late spring, flowers in early summer, is cut back once or twice, and dies down completely after the first hard frost. The rhizomes are active underground for longer than the top growth suggests, which is why the containment checks are spread through the year rather than done once.
The whole year's work is perhaps two hours in total. What matters is that certain items happen at the right moment, because a check missed in spring costs a great deal more in autumn.
| Season | Main job | Containment check |
|---|---|---|
| Late winter | Nothing above ground | Confirm the pot's position and stand are sound |
| Early spring | Shoots break, first light picking | Lift the pot and inspect the base and ground beneath |
| Late spring | Fast growth, main cut as buds form | Clear every stem overhanging the rim |
| Early summer | Flowering, regrowth after cutting | Walk the surrounding ground for stray shoots |
| Late summer | Second cut, watch for scorch | Check drainage holes and the barrier line |
| Autumn | Divide or renew the pot, lift rhizomes | Walk the whole barrier while foliage is still up |
| Late autumn | Cut to the ground and clear away | Remove all cut stems from soil contact |
Spring: the most important checks of the year
Everything is easiest now. Shoots are small and unmistakable, other plants have not covered the ground, and a rhizome that has escaped has only had one winter to travel. Ten minutes of looking in early spring saves most of the work in the rest of the year.
- Slide the pot off its stand and look underneath Do this before growth starts. A white rhizome emerging from a drainage hole can be cut off in seconds now; in six weeks it will be rooted into whatever is below.
- Scan a couple of yards around the plant Look for isolated heart-shaped shoots with reddish stem bases. Trace each back to its rhizome by hand and lift the whole run rather than snapping the top off.
- Top up the compost, do not feed Scrape off an inch (2 cm) of tired compost and replace it with fresh. Feeding produces soft, sprawling growth that flops over the rim and roots.
- Divide if the pot is solid rhizome If last season's leaves were small and pale, tip it out on a hard surface, keep one well-budded piece, and destroy the rest properly.
- Record the date of the first shoots Write down when growth broke ground and where. Comparing across years tells you when to expect buds and when to plan the main cut.
Never rake or hoe near a fish mint planting in spring. Cultivating drags rhizome fragments outward and every fragment becomes a plant.
Summer: cutting, watering and the smell
The main cut goes in as buds appear and before the white bracts open, which is when the leaves are at their best. Take up to two thirds of the clump, leaving three inches (8 cm) of stem standing, and bag the trimmings as you cut so nothing lies on damp soil.
Water is the only real demand in this season. A container that is full of rhizome dries out within a day in warm weather, and a plant that dries right through drops its lower leaves and stalls until it is watered again. Water thoroughly whenever the top inch (2 cm) is dry.
Expect the strong fishy smell whenever you cut, and expect it to be much stronger than the intact plant. Do not schedule a large cut for a day when the garden is in use, and wash tools and gloves straight afterwards because the oil stays on them.
| Job | Timing | Detail |
|---|---|---|
| Main cut | As buds show, before flowers open | Take up to two thirds, leave 3 inches (8 cm) |
| Second cut | Three to four weeks later | Only if regrowth is strong and the clump is sprawling |
| Watering | Whenever the top inch (2 cm) is dry | Often daily in a full pot in warm weather |
| Move out of sun | As soon as margins brown | Scorched leaves do not recover, so shift the pot |
| Cut out plain green shoots | Whenever they appear | Follow to the rhizome and cut there, not at soil level |
Autumn: division, rhizome lifting and the last check
Autumn is the second window for dividing and renewing a container, and the best time to reduce a planting, because the rhizomes are plump and easy to see once the top growth thins. Work on a hard surface, keep only what you intend to grow, and dry or bag the rest until it is dead.
This is also the last chance to walk a barrier line while the foliage is still standing. Once the top growth dies back, an escape three feet outside the barrier is invisible until the following spring, by which time it has had a season to run.
Finish by cutting the whole clump to ground level after the first frosts and removing every piece of stem from the site. Stems left lying on damp soil over winter root at the nodes and give you a new plant exactly where you did not want one.
Do not tip spent compost from a fish mint pot onto a border or a heap. Treat all of it as live material: dry it out completely or seal it in a bag until it has broken down.
Winter, and what to write down before you forget
There is nothing to do in winter except keep track of where the plant is. With no top growth showing, the two common mistakes are planting something else in the same spot and standing the container down on bare soil while tidying. Both only become obvious in spring, and the second one usually means the rhizomes have already found the ground.
Use the quiet season to write up the year while it is still fresh: the date shoots appeared, the date buds showed, how much you cut and when, the position of every stray shoot you found, and whether the variegation held or slipped further towards plain green. Two seasons of that turns this from a plant you react to into one you stay ahead of.
- Mark the container's winter position Note where it stands and on what. A pot moved onto soil for the winter is the commonest single cause of an escape.
- Log the season's stray shoots List each one with its date and distance from the plant. The pattern across two years shows the exit route, and closing that route is worth more than any digging.
- Note how far the variegation slipped Record roughly what fraction of shoots came up plain green. When it passes about half, it is time to renew the pot from the best-colored material you have.
- Plan next spring's check into the diary Put the early spring lift-and-look in writing now. It is the single check that catches problems while they still take minutes to fix.