Force Bulbs To Flower Indoors

At this time of the year many gardeners are burned out.

The hot and dry summer, the bugs, the weeds … they’ve all taken a toll, and it’s hard to look ahead and try to plan new projects let alone contemplate next year’s garden. But in the dead of the winter of 2021, wouldn’t you like to look out at the cold, gray (maybe white?) landscape as you sit indoors smelling the hyacinths, daffodils and tulips blooming away on the dining room table or kitchen window sill with their wondrous colors and promise of spring? It’s going to be a long and cold winter. Here’s a chance to get some spring indoors while the snow and ice melt.

If you’ve ever wanted to force spring flowering bulbs and have them bloom on demand this winter, then now is the time to take action. Bulbs for forcing need to be potted up now, and you need to shop for the bulbs in one or more of our better garden centers. Cheap orange box or hardware store bulbs won’t do for this project, but garden centers who sell loose bulbs are a great place to start. If you wait longer then you’ll be disappointed at the selection available and you’ll run out of “cooling’” time. However, by getting the work done now you have the choice of colors, sizes and varieties. And bulb forcing is much simpler than you’d think. This is a project for pandemic-inspired gardeners as well as those with experience.

Close to perfect timing is important since most bulbs that are forced — and not all can be —need from 12 to 16 weeks of cool temperatures to get them blooming indoors from January through April. So, bulbs potted up in early-October can be timed to bloom from mid-January right through late March.

There are plenty of intimidating articles and even books and precise growing guides on how to pot the bulbs, cool them to one temperature and then another and yet another, then cover them with sand and finally a regime of raising temperature exposures that will result in blooms when you want them. Well, if you want to have your tulips blooming precisely on Valentine’s Day you can follow those prescriptions, but if you want blooms around the middle of February or sometime in March, it’s really easy.

Pot up your bulbs (or practice) as soon as you have them. Newbies should probably use clay pots unless you can restrain yourself when watering, since plastic pots can retain too much moisture and encourage rot. The preferable pots are a type called bulb pans that are available from 8 to 12 inches in diameter and 4 to 6 inches deep. As an alternative, pots that are very shallow (depth about half their diameter) can be used, though standard pots can work. The increased depth can allow too much moisture in the root zone, so shallow is better. If you are using old pots, wash them well to eliminate any possibility of mold or algae build-up.

No special soil is needed but soil from the outdoor garden should be avoided and we’ve had no problems with Pro-Mix right out of the bag so long as you DON’T get it dripping wet and keep it that way all winter. Any peat-lite potting mix will do, but try to find one that doesn’t have any fertilizer or water retaining crystals in it.

The bulbs are planted so that the “nose” or tip of the bulb is just a quarter to a half inch below the top of the soil, and it takes a little practice to get the right amount of soil under the bulbs, around them and on top of them. After a pot or two you’ll catch on real quick. It doesn’t cost anything to practice, and since the whole process starts out dry you can just empty the pot, refill it and replace the bulbs until you have it right.

Take a dry run using a pot and some dry soil and the appropriate number of bulbs before you moisten the soil. Add or subtract bulbs and rearrange them as needed. This practice will allow you to space the bulbs, get them to the right level and fill in the voids with the soil. The pot should be somewhat crowded with bulbs to result in a “full” presentation when they bloom. Then once you’ve got the hang of setting up the pot(s), use lukewarm water to moisten the soil and “set” the bulbs in their beds. Bulbs can also be layered in larger, deeper pots and this results in graduated heights of blooms when flowering takes place.

With tulips, you’ll notice that the bulb has a flat side and rounded side, and the flat side should face outward. But with hyacinths and others, it doesn’t matter. A 10-inch pot is probably the most popular, and as a rule of thumb for tulips and daffodils try to get in one bulb for each inch of pot diameter and space them evenly around the pot. So, an 8-inch diameter pot can have eight or so bulbs, but if the pot is deeper you can layer the bulbs and get nearly twice that number in. Hyacinths are spaced at about half this rate so we try to squeeze five into a 10-inch pot while you can get a dozen Scilla, Muscari or Iris reticulata into the same size pot.

For now, get your pots together, and you can start collecting your bulbs, keeping them in a cool dark place until you’re ready for potting. At the garden center or online, look for bulbs that are noted as “good for forcing.”

Think about where and how you’ll cool your pots. They can go in an unheated garage or shed, an uncovered cold frame or even a backyard pit and yes, a refrigerator shelf, but more on this later. It’s probably a good idea to cage your pots or dip your bulbs in rodent repellent to keep the mice and voles at bay if you’ll be cooling the pots outside.

Using modern refrigerators to cool the bulbs presents a challenge because the frost-free functions suck all the moisture out of the bulbs (wine coolers are perfect if they’re cool enough). You can work around refrigerator issues by keeping your pots on the dry side, putting them in plastic bags and sealing them inside the fridge. And you don’t need to do all your bulbs at once. If you have the fridge space, you can do a few pots (or more) every week for a month to stagger when they’ll bloom or you can pot them all at once and just stagger when you pull them out.

The whole object of the cooling period is to stimulate the bulbs to develop roots. These roots will then supply moisture to the developing foliage and flowers once you begin the actual forcing next year. It’s the same process that the bulbs go through when planted outside in the garden. They develop their roots in the cool fall soil then go dormant until the soil warms and shoot development and flowering takes place.

In two weeks I’ll cover the steps to take and how to do the chilling process, the forcing and some varieties that I’ve had good success with. But if you want to jump right in take a look here: extension2.missouri.edu/g6550/. This is a great fact sheet with instructions and suggested varieties to use for forcing. Next week, we move to the outdoor spring-flowering bulbs, then in two weeks, I’ll finish up on bulb forcing. Keep growing.

Young perennial weeds that established in your lawn over the summer are now visible and easy to dig or for larger areas, spot spray. Use a weeding tool for small lawn areas and make sure you get the roots of weeds like plantain and dandelion. Spot sprays using an RTU (ready to use) spray bottle for broadleaf weeds can also be used but keep this stuff far from gardens and don’t spray when there’s wind. Take care of this now and you won’t need to next spring.

I used Johnny’s Cheap Frills Greens Mix for our fall veggie greens. The seeds germinated in just a few days and harvesting began less than two weeks later. The mix is pretty amazing, not bland like the lettuce mixes and when cut to 1-inch at harvest a new crop fills in just seven to 10 days. Our 2-foot-by-5-foot “greens” section of this mix is producing close to two 2-gallon plastic bags worth every week. An ounce of seed is about ten bucks. Store-bought, organic greens like this will set you back nearly five bucks per bag or box. Growing your own is simple, cheap, organic and this crop will continue for another six to 10 weeks.