Growing & Planting
Flowerbulbs can be a bit finicky, but in general are relatively easy to plant and easy to care for - we hope the following information will be of help:
When to Plant
Tulips are almost always spring-flowering bulbs and therefore MUST be planted in fall (Sept.-Dec., depending on your climate). A good bulb provider should ship your bulbs at the proper time for planting - when soil temperatures in your area are approaching 55 degrees F. It is recommended that you plant your bulbs upon receipt. If this is not possible, open all of the boxes so that air can get to the bulbs, and keep them in a dry, dark, cool place with good air circulation.
Temperatures between 50 degrees and 60 degrees F are ideal, but a range of 38 degrees to 70 degrees F should still be okay. Following these steps, you can delay planting for several weeks, but always remember that the bulbs MUST be planted before the onset of winter. See the below map for suggested planting times by region.
Choosing a Site
There are two key considerations when choosing a site for bulbs.
- Sunlight: First appearing on the wide open mountains of Central Asia, it is no surprise that Tulips need ample sunshine to bloom in the Spring as well as to store up the energy required to flower in future springs. However, it is worth noting that some bulbs, such as crocuses and bluebells, can still be planted in moderate shade, and so it is always a good practice to look into the specifics of any bulbs you purchase to understand their particular needs (a good provider should have this information ready).
- Drainage: All bulbs need good water drainage, and it is recommended to never plant bulbs where water collects. The drainage of heavy clay soils may be improved by digging in organic matter such as compost or composted manure.
How to Plant
There are two principal ways of planting bulbs.
- Planting a bed: Begin by excavating the area to be planted and loosening the soil in the bottom. Set the bulbs in the bed (typically 4-5" deep for Tulips), and be sure to space the bulbs appropriately. Standard Tulips grow best with approximately 5 bulbs per square foot of planting area, while wild Tulips can be planted a bit more densely at 9 to 13 bulbs per square foot. Replace the soil once planted, water thoroughly if the soil is dry.
- Planting individual bulbs: Dig a hole with a trowel, auger or bulb planter. Place the bulb into the hole ideally with the point up as this is where the stem will sprout from (while roots will push from the opposite end). Replace the soil, and if dry be sure to water thoroughly.
Bulbs need ample moisture from Fall, when they make new roots, until they finish flowering in spring. If the soil is dry at planting time, water thoroughly. Thereafter, water only if rainfall is scarce to ensure that the soil stays moist. Stop watering after the bulbs bloom. Supplemental irrigation after bloom - especially in the warm Southern climates - may cause bulbs to rot.
Oftentimes, bulbs shipped will already have the following year's flowers set inside them, so there will be no need to fertilize at planting time. However, if you intend for your bulbs to be long-term players in your landscape, you may want to fertilize them in early spring, when the shoots begin to push through the soil. Prior to doing so, it is recommended that you first have your soil tested to identify any nutrient deficiencies. This will allow you to correct any issues with an organic fertilizer, which will release nutrients slowly.
For the most part, though, bulbs are not heavy feeders. You can generally do without fertilizer entirely if you mulch your bulbs annually with 2-3 inches of an organic material such as compost, shredded bark, aged wood chips or shredded leaves.
Care After Bloom
After your bulbs bloom, you may remove the spent flowers or seed heads if they are unsightly (in the case of Tulips, removing the seed heads can also help to encourage the bulbs to flower again the following year). It is also recommended to allow the foliage to die back naturally - if you cut, braid or tie up the foliage before it yellows and withers, it can prevent the bulbs from producing the energy needed to grow and bloom again in the following year. Of course, if you intend to lift and discard Tulip bulbs after they bloom and replant in the fall, there's no need to wait for the foliage to yellow.
Recommendations for warmer climates
Most bulbs do well through USDA Plant Hardiness Zone 7 (see below). However, in Zones 7b-10 (where soil temperatures do not cool down sufficiently in winter and spring weather is often very warm), bulbs should be pre-chilled in order to improve the likelihood of a full, un-stunted growth.
The best way to do this is to refrigerate the bulbs for 8-10 weeks, then plant in December when the weather cools down. Once you take the bulbs out of the fridge, plant them right away, and be sure to not allow the bulbs to sit in the sun while digging (as this can warm them up and interfere with the normal growth process).
In the Deep South (and much of California), Tulips should be considered an 'annual' flower, meaning it should not be expected to grow back every year. Many understand and even enjoy this as it provides an opportunity for a new look every season, but it is important to be aware of this before purchasing for the first time. Good bulb providers can also recommend specific bulbs that will grow better in hot, southern environments.