Time for Tulips!
October 10, 2010
If you live in Texas and want to have a beautiful spring display of tulips, now is the time to get planning. Garden Centers should have their best selection of spring bulbs in-stock by about mid-October. There are a few keys to having great looking tulips that bloom on time next spring.
1. You must buy bulbs that are properly pre-chilled. Tulips require a vernalization. That means about 8-10 weeks of soil temperatures between about 45F and 50F and then a return of warm temperatures to produce a flower bud. If the bulb does not get the proper vernalization, it won't bloom. Also, if a bulb has been pre-chilled and then left out in warm temperatures for long enough, it will de-vernalize...and not bloom. You can try chilling your tulip bulbs in the refrigerator, but that only works for small quantities and most refrigerators are set colder than is optimal for tulip bulb vernalization. Then there is also the moisture and ethylene problem in the fridge.
2. Plant them on time. In my extensive experience with planting large tulip displays, the best time in the DFW area to plant tulip bulbs is about the third week of December. You have to wait until soil temperatures are consistently below 50F. The golden rule is don't plant them before Thanksgiving and try to get them planted by the end of December.
3. Plant them deep. Plant them 6"-8" deep from the tip of the bulb to soil surface. I usually plant mine at least 8" deep. The biggest mistake people make here when they plant tulips is planting them too shallow. Temperatures fluctuate more in the top few inches of the soil. So if you plant your tulips only 3"-4" deep, they will often emerge too early (especially when we have those January thaws). This can result in wimpy flowering, or the flowers being damaged by a subsequent frost. They can also blast, meaning the flower will open down at ground level. This is a result of the bulb being exposed to high temps very quickly after vernalization. By planting them deep, they will be insulated from those early warm temps and they will bloom on-time. Adding a couple of inches of mulch on top of the soil will help.
SO, to recap:
1. Only buy properly pre-chilled tulips.
2. Plant them on time: December.
3. Plant deep! minimum of 6" deep, 8" is better.
AND, you can attend my next bulb 101 class HERE