Fall tulips coming up short

Asked March 24, 2020, 5:25 PM EDT

I planted my tulips in October last year and now they are coming up only 6" tall when they should be 15" tall - I put them in 6" deep with mulch on top. How can I get them to grow their normal height?

Washington County Oregon

3 Responses

https://web.extension.illinois.edu/bulbs/planting.cfm I have enclosed very basic information about growing tulip bulbs. Without asking further questions it appears that a measure such as fertilizer could account for lack of normal development. Another factor not to be discounted is the erratic weather that we have experienced recently that may be "confusing" plants. You may wish to consult with your favorite local nursery
for advice as well.

It also could be that the variety you planted is a low-growing one. There are tulips of that type, they just aren't as common as the tall ones.

If the nearby label for 'Foxy Foxrot' is the name of the tulip cultivar, it is described as 14-inches tall.

In general, hybrid tulips (the tall, large-flowered kinds) all must receive sufficient winter chill in order to bloom well. The chill period must be for 10 to 14 weeks at 35 to 48F. (That can occur when the bulbs are in the refrigerator or the ground.) The temperatures must be consistent rather than in up and down cycles.

Several things can interfere with this process for tulips. When tulip bulbs (those large enough to bloom) receive too little winter chill, they will bloom at a shorter height than normal.

The main reason is lack of sufficient winter chill, via one of these methods:
(1) bulbs weren't pre-chilled by the producer prior to sale, then not chilled by the gardener;
(2) pre-chilled bulbs lost the benefit of chilling if they were held too long at room temperature at the retail outlet or at the gardener's place;
(3) bulbs didn't receive sufficient chill while in the ground. (This is likely the reason for these tulips; the past winter was relatively mild. Then, too, the mulch could have further inhibited the soil becoming cold enough for long enough.)
(4) A heat wave, just as the tulips come through the soil surface, or shortly after. (I'll always remember the year my tulip bed in Long Beach, California, when the tulips bloomed at ground level. They looked very strange and were a conversation point for the entire neighborhood!)

In case you're wondering, neither daffodils nor crocus need to be chilled.