Is it too late to plant my tulips?
Published 3:14 pm Thursday, February 2, 2023
I got this question from a friend this week and knew right where to go to find the answer. I called Carl Van Staalduinen, one of the owners of Terra Ceia Farms. They have grown bulbs in that area for generations.
There are a few things to know about tulips. First, let’s talk about bulbs in general. Bulb is a fairly generic term to describe several types of plants called Geophytes. Geophytes include true bulbs, corms, rhizomes, and tubers. These are basically different types of underground stems that have stored energy and have buds, leaf scars, or nodes.
Tulips come from a class called true bulbs. They are a complete plant just in the form of the bulb. If you were to dissect the bulb, you would find all the parts of the plant including the flower. We have several bulbs that we can grow in Eastern NC. These can be broken down into two main groups, Spring/Summer and Fall/Winter. The spring/summer bulbs are those that will grow during the warmer season. They will not tolerate cold temperatures and in many cases, need to be removed after the first frost of the fall to be stored. The biggest considerations with what we call fall bulbs is the amount of chilling that is required and when to plant. According to Carl, tulips need an average of around 14 – 16 weeks of cold in the 40° – 45°F range. Plants like daffodils would require slightly less.
When you plant is really important. I talked to Carl to find out more about when the best, and perhaps more importantly for folks like me, the latest time that you can plant. In true horticulture fashion, the answer is, it depends.
Some bulbs that we purchase have been refrigerated to ensure the chilling requirement has been met. If you know that your bulbs have been chilled already then you can plant them up to the middle of February. However, chilling is and is not a cumulative type of thing. We need 40° – 45°F temperatures to accrue chilling but if the bulbs are allowed to get warm, you will lose chilling time that has already been accrued. According to Carl, bulbs that have been chilled need to be planted soon after purchase. The longer they sit around at ambient temperature, the more chilling they will lose. If they haven’t had chilling, then they should be planted earlier in the season such as December so they can accrue the required chilling.
Tulips, and other bulbs, are usually planted in clumps but that doesn’t mean that you want to put them on top of one another. For instance, we can actually layer the bulbs for a bed or flower pot full of color but they still need a little space. Space allows air flow and lessens competition between the plants. Typically, tulips would be planted with 2-3” in between them.
There is another measurement we need to be concerned with and that is the depth at which we plant our bulbs. Typically, we can look at the diameter of the bulbs to gauge how deep they should go. A good rule of thumb is to plant them two to three times as deep as they are wide. A tulip bulb is going to be around 2” in a diameter so they would go 4-6” deep. This is important to protect the bulb from freezing soil and from squirrels and deer at the same time. When planting, it is important to plant the bulbs root-side down! One end of the bulb should be pointed and one should be more rounded with what looks like thick hairs (these are the roots). Plant the bulbs into good, well-drained soil that has been loosened. Gently push the bulbs into the loosened soil and then cover. If you are layering with smaller bulbs, repeat this process until you get everything covered. Layering bulbs works really well in larger flowering pots to create a great floral display on porches and high traffic areas.
Most bulbs do best in direct sunlight. There are some exceptions so do a little research on what you are planting before purchasing to make certain you are putting the right plant into the right place.
So how do daffodils do so well under the trees in the spring? The trees don’t have any leaves on them when the daffodils are in bloom so they are getting full sunlight during that time of year. By the way, Carl also told me that Terra Ceia Farms now has their fall/winter bulbs 50%!
NCSU has numerous publications and resources on growing both warm and cool season flowers. Call the Extension office at (252)946-0111 or email me at firstname.lastname@example.org to find out more. I will be starting the “What You Need to Know so You Can Grow” series in March, if you would like to know more about this opportunity, please call the office. There will be five classes in this series beginning 3/3 and running through 3/31. Classes will be from 9:00-11:00 a.m. and will cover topics soils, vegetables, fruit, lawns, and ornamentals. Those that attend every class will earn the Friends of Blacklands Horticulture certificate. I will have a commercial ornamentals and turf class coming up on February 27th at the Vernon James Center in Plymouth. If you need pesticide credits or landscape contractors credits, please keep an eye out for this class, you will receive a mailer if you have a pesticide license. Until then, Happy Gardening!