Quite unlike any other group of plants, bulbs are fascinating, and can add colorful elegance to any garden bed or container. Whether you invest in a large, single spring display of tulips or in big borders of daffodils to multiply each year, knowing how to prepare the soil and plant the right bulbs in the right spot at the right time can make a huge difference in their flowering show.
- Acidified Compost or Azalea Soil Mix— The slight acidity of both are good for growing bulbs. In un-amended clay soil, the mix is ideal. For amended soils, simply adding the acidified compost is usually enough.
- Expanded Shale— A porous, lightweight ‘gravel’ that increases drainage and aeration and helps to break up native clay soils, which is especially important for bulbs to grow well.
- Mulch— Apply at least 2-3 inches of a mulch such as Pine Bark after planting to conserve moisture, protect your investment in the soil, moderate temperatures, and deter weeds.
- Liquid Seaweed— An organic extract that strengthens plants for better resistance to temperature fluctuations, stress, and disease. Good for soaking bulbs prior to planting.
- Espoma Bulb-tone— For bulbs that are intended to multiply and cover larger areas as they grow, a good fertilizer will help them establish more quickly and prosper long-term.
- Bloodmeal— A good source of nitrogen and a good add‐on nutrient to fertilizer, bloodmeal is ideal for bulbs, and also for pansies or other annuals typically planted with them.
CHOOSING: The time to purchase bulbs can be different than when they are actually planted, so it’s best to know the season in which you want your bulbs to flower: ‘Spring’ bulbs are available to buy from early fall and just into winter– September until December or so— are planted then, are typically treated as annuals or perennials, and make their show in spring. ‘Fall’ bulbs arrive with them, but bloom in fall when temperatures first drop, such as the spider lilies. These are distinguished from the ‘summer’ bulbs, perennial bulbs that arrive in late spring for planting, and that grow and bloom only through the warm summer season.
TIMING: The most important factor in bulb success is the timing of planting. Planted too soon or stored in hot conditions, the flower inside will die, and those planted too late can cause an early, damaging bloom (called ‘blasting’). All bulbs are highly temperature driven, and therefore planting time is critical.
In general, it is best to plant most fall bulbs for spring bloom in the Dallas area after October 15th.
- Annual bulbs like tulips need cold storage or ‘vernalization’ until soil temperatures reach a stable 50 degrees, mid‐December to early January. Most other bulbs listed are perennials, and do not require chilling.
- The perennial bulbs, daffodils (Narcissi) and other irises, and many other bulbs can be planted anytime; generally from late September until March (see the CULTURE section below for details on each bulb type).
- If you’re not ready to plant bulbs outdoors, you can store them in a cool, dark place with good air circulation until you are ready to plant.
- Bulbs needing chilling can be stored in a refrigerator, though they are somewhat cold (about 40 degrees) than the preferred 45 degrees for most bulbs. Put them in labeled, plastic open‐mesh bags in the crisper, making sure they always have good air circulation around them. NOTE that any ripening fruit must be kept separately from them, lest the gasses they give off cause the bulbs to bloom prematurely.
SELECTION– Here are a few guidelines for bulbs to show their best:
Plant in masses. Most bulbs will show best this way. Many bulbs, such as tulips, need to be planted closely to get dense color. Do not plant in rows like ‘soldiers’. The larger the grouping, the greater the impact.
Mix types. For longer tulip bloom, mix ‘mid’ season varieties with ‘late’ varieties of a similar color. This will give you a bloom time that will last up to 4 weeks in your spring garden. Single, late tulips may last better in our warm spells.
Add bulbs to the permanent landscape. Some bulbs perennialize, returning for several years, or naturalize, meaning they reproduce and spread, so plan on having sufficient prepared space for these. Overplanting, or adding annuals such as pansies on top of bulbs, can make for longer‐lasting, stunning displays.
Try bulbs in containers. Bulbs mix well with annual color in containers. Cool‐season color such as pansies, violas, Iceland poppies, curled parsley and salad greens all make great companions. Use deeper pots and plant toward the center in no more than 2 layers of bulbs, protecting from freezing on the coldest nights.
Most varieties do best in part sun to sun. Tulips and hyacinths like at least 3-4 hours or more of sunlight. Daffodils and some other bulbs are excellent in part shade, and can be ideally sited under deciduous shade trees.
Whatever site you ultimately choose, the area must be well‐drained, especially when any bulbs are dormant.
Prepared, well-drained, amended soils are best, as heavy clay can freeze and break bulbs and keep some from spreading and perennializing. Most prefer moist, but well-drained soil. Be careful never to overwater bulbs.
- Add organic compost and expanded shale to heavy soils to improve drainage.
- For increased success, most bulbs will benefit from a 20 minute soak in a seaweed solution.
The recommended spacing depends on the number of varieties and planting arrangement. For reference, most annuals planted by themselves are planted 8” on center.
6″ on center
5″ on center
3″ on center (or ‘shoulder to shoulder’)
12″ on center (with pansies or other annual color on top)
One variety of tulip or daffodil
Three or more varieties
- Dig the hole to the required depth, and typically this is about 3 times the height of the bulb. If you’re in doubt, please ask us for help in‐store or online. Do not guess— the depth is all important to bulb success.
- Set bulbs, with pointed side (the sprouting side) facing upward, except for ranunculus and anemones.
- Dig slightly lower if adding bloodmeal to the bottom of the hole, and then cover with a small amount of soil that returns it to the proper depth. If you are using a bulb fertilizer without bloodmeal, then apply this above the planting on top of the soil, not placed into the hole with the bulbs.
- Then fertilize. Espoma’s Bulb-tone is a good food to use, especially if bulbs are to be combined with winter color. Avoid using stronger foods in the hole when planting, as it can burn the emerging roots.
- If digging animals are a problem, first cover the planting with poultry netting to discourage their being eaten or disturbed. Otherwise, cover the bulbs with the existing soil mix, and water well after planting.
- Add a 2-3 inch layer of mulch over the area in order to keep the soil temperature even. Pine Bark Mulch with its slight acid content is ideal for bulbs. This will give you the best results.
MAINTENANCE— During summer, maintain the original mulch level to help protect the bulbs. For the bulbs that will perennialize or naturalize, be sure to feed them again in fall, after any flowering is completed.
What do I do if it’s not spring yet, and the bulbs are already up? The bulbs are simply responding to the temperature, and you won’t be able to stop them. Give them regular watering, and enjoy.
- My bulbs are done flowering for the season. Should I cut the leaves back? Do not cut, fold over, or braid the remaining foliage. For the bulbs to perennialize or naturalize, allow any foliage to remain so the bulbs regain energy for the next blooming season. Any spent flowers can be deadheaded as they bloom. Grape hyacinths, however, can have their faded blossoms left intact so that they can reseed and spread.
CULTURE— The following are growing details for some of the most commonly planted bulbs in north Texas:
SPRING BLOOMING – no chilling required; plant as directed.
- Alliums— (Allium spp.) Plant after November 1st. Garlic relatives, the Alliums sport many varieties and colors. The smaller varieties will do better in north Texas. They usually bloom in May, and will return reliably for several years in full to part sun. Perennializes.
- Amaryllis— (Hippeastrum spp.)The larger– flowered hybridized amaryllis are tropicals and do not return outdoors, but they are ideal for forcing or in containers (see the bulb forcing section). Annual/perennial.
- Anemones— (Anemone spp.) Plant in January. These soft-petaled, 2-3” blooms of white, purples, and electric blues flower in May in sunny areas. Before planting the bulbs, soak them in water for 30 to 60 minutes until they rehydrate. Daisy and buttercup-like forms exist, and all are good cut flowers. Annual.
- Daffodils— (Narcissus spp.) Plant late September to March 1. A large group that performs very well, even in part shade. Most bloom about March in gold and yellow to white, with many being fragrant. ‘Narcissi’ usually refers to the smaller flowering varieties and ‘daffodil’ the larger, though all are Narcissus. Most return for many years, if fed the 2nd year and divided the 4th‐5th. Perennializing & naturalizing varieties.
- Leucojum— (Leucojum aestivum) Plant in October. The ‘summer snowflake’ has nodding, 3/4” white bell‐shaped blooms in late February or March. With dark green leaves, they combine well with other bulbs. Best in groups of 5 or more, they do well in part shade to sun in moist, heavier clay soils. Naturalizes.
- Muscari— (Muscari armeniacum) Plant from September to March. The ‘grape hyacinths’ earn their name from their small, purple-blue flowers. These tough, small-but-showy blooms look best in large drifts, and can even prosper under lawns, spreading their chive‐like, 8” recurving leaves topped with blooms in early through mid‐spring. Evergreen leaves appear in fall through winter. Naturalizes.
- Paperwhites— (Narcissus papyraceus) Plant from September into January. Daffodil relatives, the white blooms of paperwhites are fragrant favorites for forcing indoors. The highly fragrant ‘Ziva’ is best known, while ‘Inbal’ has the lighter scent. Outdoors, they can take temperatures of 28 degrees, and bloom in 5-6 weeks in spring, lasting longer than the larger Narcissus varieties. Yellows take 6-8 weeks. Perennializes.
- Ranunculus— (Ranunculus spp.) Plant in January. With their multi-layered, 2-3” tissue‐paper blooms, these bulbs come in almost every color imaginable. Best planted in cold, well‐drained soils. Typically treated as an annual.
SPRING BLOOMING— must be chilled first; recommended temperatures are 45‐55 degrees for 45‐60 days.
- Tulips— (Tulipa spp.) Plant after December 1st. Tulips come in just about every color imaginable, and can make dazzling spring displays with the mid– and late-season choices doing the best here. They look best in masses, so as a rule of thumb plant about 12-15 tulip bulbs per square foot of space. Annual.
- Dutch Iris— (Iris x hollandica) Plant after December 1st. This bulbous form of Iris flowers for a short time in mid-spring with blooms in light and dark blues, yellows and whites. Liking rich, well drained soils, they are best under deciduous trees, where they may perennialize. They grow to 2 feet, and are a staple of cut flowers. Annual.
- Crocus — (Crocus vernus) Plant after December 1st. One species of many, the ‘true’ Dutch Crocus are treated much as tulips in our area, as an annual for early spring color. Requiring chilling too, they are best planted in loose, well‐drained soils. Annual.
FALL BLOOMING— no chilling required.
- Lycoris— (Lycoris spp.) Plant August through November. The exotic‐looking ‘spider lilies’ are the first of all these bulbs to bloom, flowering in late summer in pink, red, or yellow on slender stalks without leaves, which appear after blooms fade early summer. They tolerate heavy soils, and prosper best with morning sun and afternoon shade such as that under deciduous trees. Water carefully throughout the summer. Perennializes.
- Saffron Crocus— (Crocus sativus) Planted in October. This showy fall-blooming Crocus is the source of the precious spice saffron. Each lilac-purple flower produces only three red stigmas. The bulbs bloom in about 40 days in sun to part shade. After bloom, leaves grow 6-12” and remain until spring. Perennializes.
Forcing Bulbs Indoors
Forcing bulbs indoors isn’t difficult, but it does require proper timing. They can make beautiful centerpieces and unique gifts during the holiday season, and can add a touch of spring cheer during the darker winter months. The easiest of these bulbs to enjoy indoors are the paperwhites (Narcissus) and Amaryllis. These bulbs do not require pre-chilling, and will bloom approximately 4-8 weeks after forcing.
- Plant in a container with a drain hole in well-draining soil (or a substrate such as decorative pebbles). Alternatively, place bulb (s) in a special bulb vase or container that will allow them to be suspended above the water with roots (if any) pointing down. (See the entries below for details on each bulb).
- Water sparingly until growth begins to appear. Keep the water level about ½” below the bulb, changing it often, and the roots will ‘reach’ for it as they grow. Or, if planting in pebbles, add enough water so just the roots are in the water, and not the bulb itself.
- Once growth is under way, begin to water regularly. Do not allow the bulb to rot from over‐watering, or, if forced in water, do not allow the roots to dry.
Amaryllis— Amaryllis will bloom in about 5-6 weeks. These bulbs benefit from a soak in a Seaweed solution 20 minutes prior to planting, and can be forced in soil or water. Keep in bright light until flowers begin to open. Once opening begins, move it out of direct sunlight. Turn the pot every few days to ensure even flowering. For top-heavy flowers, add a bit more soil, stake the plant, and tie with raffia or ribbon. For another bloom, cut off the spent flower, and feed spring through late summer. By mid-August, stop feeding and watering. When the leaves turn yellow, take out of the pot, put in burlap and put in the garage. In October, remove dead foliage, plant again in fresh potting soil, and it will bloom 7 weeks later.
Paperwhites— Daffodil relatives, paperwhites take about 5-6 weeks to force into bloom indoors, and yellow varieties up to 8 weeks. For quicker bloom, look for an emerging leaf tip. Leaves and flowers can be quite tall, so believe it or not, gin added to the water at a 1:10 ratio will act as a growth regulator and help to keep them stocky and compact. Afterward, you can cut off the blooms, and plant them outside. Paperwhites forced in water will generally not rebloom and can be composted or discarded afterward.
Hyacinths— Hyacinths forced in water take about 5-6 weeks to bloom. They should always be chilled until planting time. Keep in a dimly lit area until 1” of green growth begins to appear, then move to a brighter area. Otherwise, use the same guidelines as above with Paperwhites.