Gadenin日本語Get the appThe shape of a lupine year
A lupine dies back to a crown each winter, rebuilds a full clump of fingered leaves through early spring, flowers in late spring and early summer, often flowers again in a smaller way after deadheading, then makes fresh foliage and shuts down. The season is front-loaded: the important decisions all fall between the first shoots and the end of the first flush.
It also has a shorter arc than most perennials. Peak years are the second to the fourth, and by the fifth the plant is winding down. That means propagation is not an occasional job but part of the annual routine, timed to spring when the new shoots are the right size for cuttings.
The table is a checklist and the sections below give the reasoning. Seasons are used rather than dates.
| Season | Main job | Also worth doing |
|---|---|---|
| Late winter | Clear old leaves and debris away from the crowns | Check that no crown is sitting in standing water |
| Early spring | Protect emerging shoots from slugs day and night | Mark which shoots are seedlings and pull them |
| Mid spring | Take basal cuttings from the plants worth keeping | Sow a small batch of scarified seed; set supports |
| Late spring | Watch the growing tips for lupin aphid twice a week | Water deeply if dry while buds are forming |
| Early summer | Deadhead each spike the day its tip finishes | Soak after cutting to encourage a second flush |
| Midsummer | Keep checking for aphids on the fresh regrowth | Strip mildewed leaves; cut tired plants back hard |
| Late summer | Let the fresh rosette build; no feeding | Plant out rooted cuttings and strong seedlings |
| Autumn | Cut down and remove every leaf from around the crown | Mark crown positions before the plant disappears |
| Winter | Leave the crown alone; keep it dry, not covered | Review notes and decide which plants to replace |
Spring: cuttings, slugs and getting the plant off to a clean start
Begin before the shoots appear by raking away last year's leaves and any mulch that has drifted against the crown. Mildew spores overwinter in that debris and reinfect the new growth from below, and a wet mat against the neck of the plant is the classic start of crown rot.
As the shoots come through, the priority is slugs. New lupine shoots are thick, soft and irresistible, and a fortnight of grazing at that stage can cost the whole season or kill a young plant. Protect from the first shoot until the leaves are three or four inches (8-10 cm) across and no longer soft.
When those shoots are three or four inches (8-10 cm) tall, take basal cuttings from every plant you actually want to keep. Cut a shoot away right at the crown with a sharp knife, taking a sliver of the firm crown tissue with it, trim off the lower leaves and set it in a gritty, free-draining mix in a shaded, cool place. Rooting takes four to six weeks. This is the only method that keeps a particular color, since seed does not come true.
Finish spring by pulling every shoot that has appeared outside a crown you planted, which is how self-sown seedlings are dealt with before they take over, and by putting supports in place while the leaves are still low. Do not feed and do not mulch with manure.
- Clear the crowns in late winter Rake off old leaves, stems and drifted mulch and bin them. This removes the mildew reservoir and stops the crown sitting wet as growth begins.
- Defend the shoots from slugs Start the moment the first shoot shows and keep it up for a fortnight. Clear hiding places nearby and check after dark on damp evenings; this is the period when young plants are actually lost.
- Take basal cuttings at three or four inches Slice a shoot off flush with the crown, taking a sliver of firm tissue with it, strip the lower leaves and root it in a gritty mix in a cool shaded spot. Expect roots in four to six weeks.
- Pull the seedlings Remove anything growing outside the original crown, roots and all. Hybrid seedlings revert to muddy blue and purple, grow faster than the parent and will replace it within two seasons.
- Support, do not feed Put canes or a ring in while the foliage is low so stems grow up through it. Skip the fertilizer entirely; the plant fixes its own nitrogen and feeding produces soft floppy growth.
Summer: aphids, deadheading and the second flush
From the point where buds are visible, go over the growing tips and young leaves twice a week. Lupin aphid is unmistakable when you find it, a gray-white crust of unusually large aphids on the stems and spike, and it goes from nothing to a ruined spike in under a week. Hose colonies off, wipe out what the hose misses, and repeat for several days rather than assuming one pass has done it.
Water deeply during the fortnight when the spikes are building if the ground is dry, wetting the top eight to ten inches (20-25 cm). Drought at that moment aborts the upper buds and gives you a spike with a bare green tip, which cannot be corrected once it has happened.
As each spike finishes at the tip, cut the whole flower stem down to a leaf joint or to the base. Do this within a day or two rather than at the weekend. Prompt cutting stops the plant pouring its season into seed pods, which is what shortens its already short life, and usually brings a second flush four to six weeks later. Give the plant a good soak after cutting and no feed.
By high summer the foliage is often tired or mildewed. Once the last flowers are truly finished, cut the plant back to two or three inches (5-8 cm) and let it push a fresh clean rosette, which takes three or four weeks. Late summer is also the time to plant out the rooted cuttings you took in spring, so they have their roots down before winter.
Autumn, winter and the notes that make next year easier
Once the foliage yellows, cut the stems down to two or three inches (5-8 cm) and take every leaf and stem fragment away from the crown. Bin it rather than composting it, and do not leave it in place as winter cover. That debris is the mildew reservoir for next spring and a wet blanket against a crown that dislikes damp.
In winter the plant wants nothing except drainage. Lupines are hardy well below freezing and cold is rarely what kills them; standing water over the taproot is. If a crown sat in a puddle last winter, plan to lift and replant it on a slight ridge in spring, or accept that it will not last. On containers, tip the pot so it drains and raise it off the ground.
Autumn is a good moment to plant, provided you allow six weeks before the ground freezes, and to move anything that flowered badly because of shade. Mark the position of every crown before it disappears; a lupine is invisible from autumn until well into spring, and a fork through a dormant crown is the most common accidental loss.
Use the quiet weeks to go through the season's notes plant by plant: the date the first spike opened, how many spikes each carried and how tall, the color each actually flowered, whether a second flush followed and how long after cutting, when aphids first appeared and on which plants, and which crowns failed to come up last spring. Those entries answer next spring's real questions before you have to guess them: which plant is worth taking cuttings from, which one is finished and should be pulled, which corner of the bed is too still or too wet, and how many replacements you need to have ready.
Plan replacements every year rather than every fourth year. With a few rooted cuttings and a small batch of seedlings coming on each season, the loss of an old crown is a gap you filled in advance instead of an empty space in the middle of the border.