In a few months we’ll be in the middle of winter, and many of us will be yearning for spring. Forcing bulbs to bloom indoors can be the perfect way to bring a little cheer into our winter rooms.
Forcing bulbs is incredibly easy, but it does take a bit of advance planning. Actually, quite a bit: essentially what you are doing is tricking the bulbs into thinking that they are going through a winter dormancy and then emerging into spring. But unlike the natural cycle, this winter starts in October and ends in January or February.
The most common bulbs for forcing are tulips, daffodils, crocus and hyacinths. You can also force irises, snowdrops, amaryllis and paperwhites.
Those last two are a bit of an anomaly. Because they are native to the tropics, they don’t need a chilling period. So you can plant them at any time and they will begin to grow. You can even plant them in succession, and enjoy a solid season of blooms all winter long.
For all other bulbs, though, you need to give them some time in a dark, cool environment. The amount of time depends on the bulbs. Grape hyacinths and crocuses need at least 8 weeks. Hyacinths need 10-12 weeks. Tulips, daffodils and most other bulbs need 12 to 15 weeks. Planting them now means you’ll be enjoying blooms in late February.
If you can’t plant the bulbs right away, keep them cold — in the crisper drawer of the fridge is ideal. Avoid keeping them with apples, though, which give off a gas that causes other fruit to ripen or rot.
The most common method of planting bulbs is to simply put them in soil in a container.
Select a pot that is roughly twice as deep as the bulbs are tall. Get some high quality potting soil, or a mix of equal parts soil, peat and sharp sand, and fill the pot one third to one half full.
Place the bulbs in the soil, being sure to put them the right way up! Bulbs do best if they’re planted in groups — close to each other, but not touching. The top of the bulbs should be even with the rim of the pot.
Tulips have a flat side, which is where the first leaves emerge. If you place these bulbs so that all the flat sides are facing the same way, they will have a nice uniform look when the leaves start to emerge.
Fill the pot with soil, ensuring that the necks of the bulbs are sticking above the soil — bury them entirely and they will rot.
Water the pot lightly, and place it in a cold, dark location. A cold room is ideal, or a fridge if you have space. You want somewhere that is five to ten degrees — not a sub-zero garage.
During this period they are growing slowly, so you need to keep the soil moist, but not wet. Check it once a week or so, and mist if necessary.
When the cold period is over, you can gradually introduce the bulbs to some warmth and light. Indirect light and cool temperatures are best for a few weeks — essentially mimicking the early days of spring. Once the first flower buds emerge, you can move the plants into full light and warmth, and enjoy the blooms. In most cases it will take three or four weeks from the time they emerge from storage until the blooms open.
Once the blooms die, you can simply discard the plants in the compost — they can’t be forced to bloom a second time. However, if the bulbs are hardy for this area, you can also let the plants mature and ripen.
Once the leaves have died back completely, remove the bulbs from the pot and store somewhere cool and dry until autumn, then plant them in the garden.