Forcing Tulips

Many of my clients love tulips, wanting them planted in their gardens to enjoy for years to come.  They show me catalogues that are marked with the tulips they want: frilly parrots, fancy long-stemmed varieties, or specifically chosen color palettes to fit in their garden. They always look a little crestfallen when I tell them that these beauties don’t really do well in our mild climate and might be best considered as annuals, after refrigerating them first for several weeks.

Once they adjust their expectations, they’re usually fine with this alternative.  After all, there’s something deeply gratifying, almost hopeful, about planting a bulb in the winter, knowing deep down that the dreary weather will eventually end and spring will soon arrive.

Why do we need to chill our bulbs?  For those of us who live in California (or one of the Sun-Belt states), we don’t have the necessary winter chill that most tulip bulbs require.  Tulips must have a long period of time where the soil temperatures are 45 degrees or colder.  Since temperatures in my region don’t meet this chilling requirement, tulips are unlikely to re-bloom.  Without chilling, they may still flower, but they tend to look nothing remotely similar to their description in the catalog.

Forcing dormancy is simple – put them in the refrigerator for at least 6-8 weeks.  Shoot for a goal of planting them in the ground in January, which would give them plenty of time to grow and flower in the spring, before the hot temperatures of summer arrive to put an end to their show.  This means you need to buy your bulbs now and have them in the refrigerator by mid-December at the latest.  Place the bulbs in a brown paper bag, or keep them in the bags they come in, and don’t let them get wet – otherwise they’ll mildew and they’ll be good for nothing but the composter.  The mini-fridge in my garage houses several bulbs for about 10 weeks each year (it took awhile, but my family is used to it by now!)

Note:  It’s very important you do not store the bulbs in the same refrigerator as your fruit!  Big mistake!  Apples and other fruits give off ethylene gas as a natural part of ripening, and this gas is bad for bulbs.

Another Note: If you live in warmer climates, and you don’t want to go through the effort of forcing bulbs, there ARE bulbs that thrive with no winter chilling!  They’re not the long stemmed varieties or the frilly parrot tulips, but they’re beautiful nonetheless and over time they’ll naturalize into charming colonies that welcome spring’s arrival.  These are T. clusiana (Lady Tulips), T. saxatilis (Candia Tulips) and T. sylvestris (Florentine Tulips).

How to plant tulips? Many of us have seen those gardens who have their tulips all lined up like little soldiers.  I prefer a more naturalistic planting by laying the bulbs out in an informal mass, with curves and asymmetrical shapes.  I know gardeners who throw handful of bulbs out and wherever they land, that’s where they’ll be planted.  Either way, it’s best to plant groupings of odd numbers, since even numbers tend to look formal and un-natural. Plant the bulbs 4-6 inches below the soil, with their roots or basal plates facing down. I always amend each hole with a handful of good quality, organic bulb fertilizer.  Water when finished, and add mulch to retain the soil’s coolness.

In the spring, make sure the bulbs are receiving regular water, and feed them a few times with diluted liquid fertilizer while they’re growing. A low nitrogen fertilizer is best so the energy isn’t all going into the leaves causing rapid leaf growth at the expense of flowers (look for a 9-9-6 analysis).

After the flowers have disappeared, do NOT cut down the foliage.  The leaves are busy storing energy from the sun for next year’s growth.   Lots of people hate looking at the messy clump of leaves.  If that’s the case with you, then place a mounding plant in front of the bulbs to hide the shriveling leaves.  You can also use a plant support, such as this, to pin the leaves to the ground, creating a tidier look (especially in the wind).  Once the leaves have completely shriveled up, you can gently dig up the bulb and set it in a cool, shady spot for the rest of the summer.  Come fall, refrigerate it and start over again!  You’ll get at least a few year’s worth of blooms by doing this.

For those clients who think this is too much of a hassle, I recommend planting your chilled bulbs in a container and setting it out of the way for the winter.  Come spring, bring it onto your patio or near your front door to enjoy for several weeks, then compost the bulbs and start over again in the fall.

Or, you can do what I do and find someone to donate the bulbs to.  My mother lives in an area that gets sufficient winter chill, so she’s the lucky recipient of all of my container bulbs – and I get to see them blooming happily year after year in her garden!