Gadenin日本語Get the appAutumn: plant, and start the chilling
The garden year starts in mid-autumn, once the soil has cooled to about 55F (13C) and four to six weeks before the ground is likely to freeze. Plant six inches (15 cm) deep and six inches (15 cm) apart, with grit under the basal plate on heavy soil, wearing gloves throughout. Water once and mark the position.
The same weeks are when indoor forcing begins. Count backwards from the date you want flowers on the table: roughly thirteen weeks of cold and dark, then three to four weeks of gradually increasing light and warmth. Sixteen weeks is the working total for unprepared bulbs. Prepared bulbs need about seven weeks in total, so they can be started much later.
Late autumn is the moment to check on anything in the dark: bowls should be barely damp, glasses should have water a quarter of an inch (5 mm) below the basal plate, and nothing should be softening. Top up water levels and put the cover straight back on.
Winter: watch, do not water
Outdoors there is nothing to do. Roots are growing in cold soil and the bulbs need no attention, no feeding and no mulch beyond whatever is already there. Resist the urge to poke about; a fork going into a marked group in midwinter is the main hazard of the season.
Indoors this is when the cold period ends. Check the pots and glasses monthly. When a shoot of one to two inches (3 to 5 cm) has emerged and the roots are strong, move the container into a cool bright room at around 50F (10C) for a week, then to a warmer room. Turn it a quarter turn daily from the first day in the light.
Staggering matters if you want a long indoor season. Bring one bowl out every fortnight rather than all of them together, and you will have hyacinths in flower over two months instead of two weeks. The rest stay cold and dark until their turn.
Late winter is when the first noses appear in the border in mild climates. Nothing needs doing, but it is worth a look for slug damage on the emerging shoots and worth checking that no bulb has been heaved up out of loose soil by frost. Push any that have back down and firm the soil.
| Season | In the garden | Indoors, forced bulbs |
|---|---|---|
| Mid autumn | Plant at 6 in (15 cm), water once, mark | Start the cold dark period |
| Late autumn to midwinter | Nothing; roots growing | Check moisture monthly, keep dark |
| Late winter | Shoots appear; check for slugs | Move to cool light when shoots are 2 in (5 cm) |
| Early spring | Flowering; support leaning spikes | Flowering; keep at 55 to 60F (13 to 16C) |
| Mid to late spring | Deadhead, feed with high potassium | Feed pot-grown bulbs, keep in light |
| Early summer | Leaves yellow, stop watering, lift if wet | Dry off pot bulbs; discard water-forced |
| Mid to late summer | Dormant; keep dry, do not irrigate | Store bulbs dry at 60 to 65F (16 to 18C) |
Spring: flower, deadhead, feed
Flowering runs for two to three weeks depending on temperature. A cool spring stretches it; a warm one shortens it sharply. If heavy rain is coming and the spikes are dense, put a cane and one soft tie beside anything already leaning, or cut the best spikes and bring them indoors.
The moment the last floret browns, cut the flower head off and leave the green stem standing. Then feed with a high-potassium liquid feed every ten days, and keep the ground watered if the weather turns dry. This six-week window is when next year's flower is built.
Expect the spikes to be looser than they were the previous year. That loosening is the normal course of a garden hyacinth and not a sign of anything going wrong.
- Cut the spent truss Take off the flowering portion as soon as the last floret browns, leaving the bare green stem. Wear gloves if you are doing more than a few, because the stem sap causes the same itch as the bulb scales.
- Start feeding High-potassium liquid feed, the sort sold for tomatoes, every ten days from deadheading until the leaves yellow. Avoid high-nitrogen feeds, which make soft bulbs prone to rot.
- Keep the soil moist while leaves are green Water in dry spells right through the rebuilding period. A bulb refilling itself in dry soil simply stores less and gives a thinner spike next spring.
- Leave the foliage entirely alone No cutting, no tying, no folding. Wait until the leaves are yellow and pull away with a light tug, usually six to eight weeks after flowering.
- Log the flowering dates Note first open floret, last floret, spike height and how dense the truss was, per group. Those four figures are what tell you next year whether a group is settling normally or declining.
Summer: keep them dry
Once the leaves have gone, stop watering that ground completely. The bulb is differentiating next spring's flower inside itself in warm dry conditions, and standing water in warm soil is the one thing that reliably kills a dormant hyacinth. Do not mulch over the top with anything moisture-retentive.
Lift only if you need to: if the ground stays wet in summer, if the clump is congested, or if you want the space. Lift after full die-back, cure for a week in an airy shaded place, sort hard and discard anything soft, and store in paper bags or open trays at 60 to 65F (16 to 18C) away from ripening fruit.
Bulbs forced on a glass in plain water are done and should be composted. Bulbs forced in compost, kept fed and grown on until the leaves yellowed, can be dried off and planted in the garden in autumn; they will flower thinly for a year or two before settling.
Late summer is when you plan. Look back over the flowering notes and the discard count from lifting, decide which groups are worth keeping and which spots have proved too wet, and order what you need in time to plant in the middle of autumn rather than at the end of it.
If you intend to force bulbs indoors again, buy or set aside fresh bulbs in late summer. Garden bulbs and previously forced bulbs will not produce the dense truss that forcing is worth doing for.