Tulips might only bloom in the spring, but their growing season actually begins in late summer or early fall, depending on your location. Knowing what’s happening with your tulips all year long will help ensure a plentiful spring garden.
Tulips need to be planted in the fall to allow them to begin their life cycle. Ideally, they should be planted early enough so that they can begin to form a good root system before the ground freezes, but late enough so warm weather doesn’t cause them to try to bloom. Generally speaking, the best time to plant tulip bulbs is about two weeks before the average first frost date in your area. Check with your local Cooperative Extension Office for first and last frost dates where you live.
Tulips need several weeks of cold weather to gear up for bloom time in the spring. On average, the soil temperature needs to be below 50 degrees Fahrenheit for about eight weeks. If you live south of USDA Hardiness Zone eight, you will probably have to “force” your bulbs, or fool them into thinking the weather is colder than it is.
Depending on the variety you’ve planted, tulips will begin to bloom from late winter into late spring. If you are growing hybrid tulips, once the bloom begins to fade you should remove it. This will allow the plant to put all its energy back into the bulb so that it can produce another flower next season. If you are growing wild or botanical tulips, however, you should allow the flower to go to seed, so that your tulips will spread.
In both cases, you will want to allow the leaves to yellow and die off naturally, keeping the plants well watered during this time. If you plan to replace your tulip bulbs every year, you can skip this step, but if you are trying to naturalize or perennialize your tulips, this time is important, as this is when the tulip stores its energy for next spring. Avoid cutting the greenery, or braiding or tying the leaves. Allow them to wither and die off, then gently pull them away from the bulb.
Once the leaves have yellowed and been removed, you should stop watering your bulbs. Tulips need a dry warm period in the summer months. For hybrid varieties you might choose to lift, or dig up, your bulbs and store them elsewhere. This isn’t strictly necessary, however, and most people find it to be a hassle. As long as your summers are dry, your bulbs should be fine if left in the ground.
Wild, botanical, or species tulip varieties are particularly adept at spreading and returning year after year. Some hybrid varieties, such as the Darwin Hybrids and Emperor Tulips are bred to return for several years, needing replacement only when they stop producing flowers. Most hybrid tulips, however, should be treated as annuals and replanted each fall.
By knowing a bit about the life cycle of tulips and what tulip varieties you plan to grow, you can be sure to get the most out of your tulip beds this year, and for many years to come.Photo by Delphine Devos