Bulbs That Are Ready To Go
Paperwhites Narcissus, usually just called Paperwhites, are the easiest bulbs to grow indoors. They are a warm-climate bulb and therefore don’t need the cold treatment necessary for the other bulbs. They can be planted in soil in a regular pot, but work best in a closed container filled with pebbles. Plant a few every week, fill the container with water and replenish the water so the roots never dry out. Do no completely submerge the bulb. Put them in a cool, sunny spot – if grown in the dark they will get too tall. In about 3-5 weeks, you’ll have clusters of incredibly fragrant white blooms.
Amaryllis are possibly the most spectacular winter blooming bulbs and are amazingly easy to force once the bulb is mature. Plant them in a pot which is about 1″ in diameter larger than the bulb. This is usually a 6″ pot. Plant so that the soil is about 2″ below the tip of the bulb. The bulb should protrude about 1″ out of the pot. Keep these bulbs warm – 70-85 degrees is ideal. Water them in thoroughly but allow them to dry out slightly for the first week or two to encourage root growth; be sure to keep water out of the tip of the bulb. Given this minimum attention, these will bloom about 1 month after the bud stem starts to emerge. They don’t need sunlight until the bud stem is about 4-6″ out of the bulb.
Bulbs That Need A Cold Treatment
Nothing will brighten the dark days of winter quite as beautifully as a few pots of spring flowering bulbs in bloom during January and February. This is called “forcing” bulbs. Forcing is simply a matter of giving the pots a cold “winter” period to trigger their growth cycle. This may sound complex but it isn’t difficult.
When selecting bulbs for forcing, be sure that the variety you choose will force well, as some make better showings than others. Be sure to select large, unblemished bulbs. Use bulbs which are approximately the same size in each pot so your finished plants will be more uniform.
Your potting medium for bulbs should consist of a good packaged potting soil or a mixture of soils and about 1/3 peat moss. The bulbs themselves don’t seem to care what kind of pot you use for them as long as it has a drainage hole in it. However, most bulbs seem to look better and are more easily watered correctly if planted in a shallow pot. If you use old pots, be sure they are well scrubbed to avoid disease. Clay pots should be soaked in water overnight before using, so they will not steal water from the bulbs and soil after planting.
Be sure to select the correct pot size for the number of bulbs you wish to plant. A 4″ pot will hold 3 tulips or 1 large hyacinth or daffodil. A 6″ pot will usually hold six tulips or 3-4 large hyacinths or daffodils. For a real treat, try a Dutch Garden with 1-2 of each, all planted in the same pot. You will want to leave enough room so each bulb does not touch the other bulbs or the sides of the pot. Tip: for best potting of tulips, plant them so the flat side of the bulb is to the outside. The first leaf sprouts for this side and will serve to frame the blooms.
First, fill the pot with a little soil, then set the bulbs on it so bulb tops are even with the rim of the pot. Fill in the pot with the soil up to approximately 1/2″ from the rim. Finally, soak the pots thoroughly. The easiest way is to set them in a closed basin, water from above 2 or 3 times to firm the soil, and then let them stand in the water for a while to be sure they are well saturated.
The Cold Treatment
Now for the forcing part. Ideally, bulbs should be allowed to form their roots with temperatures of about 45-50 degrees for the first two weeks, with the temperature then dropping to about 35 degrees. If you are doing several pots, the traditional way to do this is the way nature does – right in the ground. Dig a hole about 18″ deep and set the post on a 1 or 2″ layer of gravel for drainage. Cover them about 2″ deep with sand and then fill in the rest of the hole with soil and mulch the top with straw, compost, leaves of grass clippings.
If you don’t have a place to bury the bulbs, there are alternatives. You can set them in a cold frame and insulate them with a mulch of straw or perlite. Or, they will work well placed in an unheated garage or cellar or even a crawl space, where they will get down to at least 40 degrees but NOT BELOW 32 DEGREES. If you have an old refrigerator, that is also ideal. In any of these cases be sure to check the pots for water every week or so to make sure they don’t dry out.
Ending The Cold Period
Whichever method you use, the forcing period should last at least 10 to 12 weeks. Check the pots and if you see roots through the drainage hole and the sprouts are 1-2″ tall, you’re ready to bring them in. (When digging buried pots, be careful not to injure the new shoots – the layer of sand will tell you about where they are.) Bring them into a cool spot at first, 50-55 degrees if possible, which is not in direct sunlight. Then, when the shoots have greened up, move them into direct sunlight. Be sure to keep them well watered.
For a succession of blooms, bring in a few pots every one and a half to two weeks. The flowers will last the longest in a cool location and can even be moved into the refrigerator at night.
Planting Your Forced Bulbs Outside
When the flowers fade, cut the flower heads off but keep the leaves to ripen-growing in a sunny place until you can plant them in the garden in April.
Bulbs you intend to plant outside should have a more nutritious potting mix. Add a level teaspoon of bone meal for each quart of potting soil and mix it in well.
Helpful Tips For Each Variety
Crocus: Use the giants only. Blue is most successful.
Daffodils: All are easier than tulips. Not as sensitive to varying temperatures as hyacinths and tulips. Tete a Tete, Ice Follies, and the large yellow trumpet varieties are most popular.
Dwarf Iris: Reticulata (blue) is the easiest.
Grape Hyacinths: Blue, white, and pink are best. Exotic colors are more difficult and not usually forced.
Scillas: Blue and white are easy but need 8-10 bulbs per pot to be showy.
Tulips: Stay with short and medium height (6-14″) varieties only. Tall ones fall over. Watch for our dots on boxes to indicate good forcing qualities.
While it’s naturally best to follow all these directions as exactly as possible, remember that bulbs are already self-contained and just waiting to bloom. Minor variations are tolerated. You’ll be surprised at the simplicity of the entire process. When your friends and neighbors start admiring the colors of spring you brought indoors during the coldest, gloomiest parts of winter, you’ll be able to smile and let them tell you what an expert gardener you must be!