Tulips (Tulipa spp.) are true bulbs. A true bulb is a structure containing a modified stem in the form of a basal plate, scales or rings, a shoot and a protective, papery tunic. It is a miniature plant containing all the necessary food to protect it during winter dormancy and to support flower production in the spring.
From a Botanical perspective, tulips are perennial. They may come back for several years provided they have an ideal habitat – cold winters, winter-spring moisture, sunny location, dry summers and good drainage.
Tulips are grouped by shape and bloom time, rather than by strict botanical or genetic distinctions. Depending on the variety, tulip flowers may be single, double, ruffled, fringed, or lily-shaped. The original ‘Species’ tulips have a limited colour range of mostly reds and yellows, and tend to have smaller flowers than modern cultivars and hybrids, which come in a variety of bright colors and pastel shades. ‘Species’ tulips are hardier than hybrids. Years of hybridizing has weakened the bulb’s ability to come back year after year. Many gardeners treat hybrid tulips as annuals and replant new ones every autumn.
One of the most reliable perennial, mid-spring bloomers with deep colours and strong stems is Darwin Hybrid tulips. This is an example of a hybrid that is a stronger ‘perennializer’ than the originator species.
Planting and Cultivating:
- Tulips bulbs are planted in the autumn from mid-September until the ground freezes. The soil needs to have cooled off from the summer growing season before you plant.These bulbs will bloom the following spring.
- Buy your bulbs from a reputable supplier. Select a range of early, mid, and late blooming varieties to have tulips blooming from April until June.
- Plant tulips in a sunny location that has good drainage. If your soil is sandy or clay, amend it by adding organic matter such as compost. This will improve the soil structure and add porosity.
- Plant bulbs 15 – 20 cm (6 – 8 inches) deep, or about three times the diameter of the bulb, with the pointy end up. Dig the hole deeper to loosen the soil and allow drainage.
- Bulbs can be planted 8 – 10 cm (3 – 4 inches) apart, or for a more impressive display,plant bulbs in groups of 5 to 10. They can be planted quite close together.
- Cover with soil and press firmly to eliminate air pockets. Water well after planting.
- Deadhead tulips as soon as the flower is gone, leaving as much of the plant stem as possible. DO NOT remove the leaves. This allows energy to be channeled back into the bulb for next year’s blooms. After the foliage turns yellow and dies back, it can be cut back. This could take 6 weeks.
- Planting tulip bulbs in containers is possible. Plant in the fall and use a container that will allow a planting depth similar to planting in a garden. You will need a strategy for keeping the containers cold, dry and insulated over the winter, such as covering the bulbs with mulch, grouping the containers so they insulate each other, wrapping the containers with styrofoam and burlap or moving them to an unheated garage. The goal is to keep the bulbs above freezing.
Pests and Diseases:
In general, tulips are very disease resistant.
- They can be prone to fungal infections.
- Tulip fire is caused Botrytis tulipae The stems and leaves will become stunted and later display brown patches. The bulbs should be dug up and destroyed.
- Tulip grey bulb is a rot caused by Rhizoctonia tuliparum. The planted bulb with dry out and produce distorted shoots that will wither and die. The bulbs should be dug up and destroyed.
- Squirrels, voles and mice find tulip bulbs a real delicacy.
- The bulbs are most vulnerable just after planting because the soil is loose and easy to dig, and squirrels are attracted by the odor of any papery tunic debris you may have dropped during the planting process.
- Laying chicken wire on the soil over the newly planted bulbs will prevent the squirrels from digging them up. Tulips will grow through the wire in the spring.
- Sprinkling blood meal on the surface of the planting area is another deterrent. This is a nitrogen fertilizer and quite harmless but this can attract carnivorous animals.
- Plant species tulips or intersperse tulips with daffodils, allium, and fritillaria. These have an odour that discourages rodents.
- Voles will tunnel underground to eat the bulbs, but generally do not tunnel as deep as 20 cm (8 inches). Plant deep.
American Meadows. “How To Grow Tulips”. americanmeadows.com/flower-bulbs/tulip-flower-bulbs/how-to-grow-tulips
The Amsterdam Tulip Museum, Netherlands. “The Tulip”. amsterdamtulipmuseum.com/tulip
Boeckmann, Catherine, “Growing Tulips”, The Old Farmer’s Almanac. almanac.com/plant/tulips
Dutch Grown, “How to Grow Tulips”. dutchgrown.com/blogs/how-to-guides/how-to-grow-tulips
Licata, Elizabeth, Fine Gardening – Issue 148, “How To Plant Tulips in Pots”. finegardening.com/article/how-to-plant-tulips-in-pots
Gardening Know How. “Information About Tulips. gardeningknowhow.com/ornamental/bulbs/tulips
Mrgich, Barbara, Adams County Master Gardener. “Ten Steps to Success With Tulips”. emmitsburg.net/gardens/articles/adams/2013/tulips.htm
Rushing, Felder, “Hardy Tulips That Bloom for Years”. hgtv.com/outdoors/flowers-and-plants/flowers/hardy-tulips-that-bloom-for-years
Date Revised: February 2022
Prepared by the Toronto Master Gardeners, these Gardening Guides provide introductory information on a variety of gardening topics. Toronto Master Gardeners are part of a large, international volunteer community committed to providing the public with horticultural information, education and inspiration. Our goal is to help Toronto residents use safe, effective, proven and sustainable horticultural practices to create gardens, landscapes and communities that are both vibrant and healthy.
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