Spring Flowering Bulbs
In parts of the world where summers are too hot or too dry for most plants to maintain growth, or where winters temporarily make growth impossible, evolution has produced a plant form that thrives. The term “bulb” has a distinct structural definition separate from corms, tubers, rhizomes and tuberous roots but these all share characteristics of buds and fleshy storage plant tissues underground. They are all loosely called “bulbs”.
Bulbs behave in some ways like seeds. Each is a storehouse of energy and resources (nutrients, enzymes, and water), all gathered only while spring soils are still moist, that will carry the plant through the harshest conditions in a dormant state until spring conditions stimulate growth the following year. Like the root systems of other hardy herbaceous perennials, bulbs are essentially chemical “batteries” that are able to convert stored energy into brilliant flowers (very energy expensive) and into natural solar panels (leaves). The leaves combine abundant CO2 and sunlight to recharge the bulb (the battery) after flowering. Our native bulbs include species of Allium, Brodea, Camassia, Calochortus, Erythronium, Fritillaria, Lily, and Triteleia among others.
Bulbs are delightful anywhere you plant them, along the street, around a mailbox, in a rock garden, in a wildflower meadow, under trees and shrubs, or even throughout your lawn.
• Adding a long-lasting organic or mineral fertilizer with nitrogen and ample phosphorus will encourage strong roots and large blooms for the spring AFTER next. Plant food applied now will help facilitate the bulbs’ recharging after next spring’s bloom. Biosol or Fish Bone Meal are great natural fertilizers for bulbs.
• Bulbs thrive in loose, organic soil with good drainage. Amend our concrete-like mineral soils with a finished compost (Kellogg’s Amend, with rice-hulls, is our go-to for bulbs). Add ~25% compost (along with organic fertilizer) to help keep the soil from compressing around the bulbs as they increase their numbers
• Many bulbs are extremely deer and rodent resistant. All of the hardy Narcissus species (including Daffodils) that thrive in our climate and persist for decades, will bloom every spring without ever being molested. Allium, Colchicum, Fritillaria, and Scilla, also have species with very strong repellence. A few bulbs are attractive to rodents. Large tulips and giant Crocus can be planted surrounded by sharp gravel or in a “root-guard” mesh bag (the smaller rock-garden tulips and bunch-flowering species crocus are seldom eaten).
• In general, we start planting bulbs by mid-September. Bulbs can be planted from September through March if you store them in a cool dark location and if you can reach the soil (I have dug through several feet of snow and chipped up the frozen soil surface several times to plant bulbs in January). Bearded iris, and autumn blooming crocus should be planted early, Late August – September if possible. Some native bulbs are only available growing in small pots and we often carry species of Allium, Brodea, Camassia, Calochortus, Erythronium, Fritillaria, Lily, and Triteleia.
• Plant bulbs en masse. Bulbs look arresting when planted in patches and swaths. Dig one wide hole, 8 inches deep. Add compost and fertilizer, and place several (or many) bulbs in one wide hole. As a general rule, place bulbs twice as far apart as their diameters (e.g. plant 2” diameter daffodil bulbs 4” apart in a wide hole). Consider blooming time (March – July), height (1 inch – 4 feet), bloom size (1-10 inches) and color (every color of the rainbow to match with your other flowering shrubs and perennials). It’s great to plant deeper larger bulbs first with smaller bulbs in a shallow layer above for a greater effect in the same hole. Placing a few individually planted bulbs near the masses gives the impression of naturalization and planting individual bulbs in wildflower gardens is a common practice.
• As with ALL plantings, a loose woody mulch is beneficial (especially in drier and colder areas with less reliable snow cover). Mulching shades and protects the soil, moderating temperature swings, slowing freezing and thawing, preventing soil moisture loss, and providing a lasting source of soil humus as the wood decomposes.
• After the flowers fade in early summer, the leaves are collecting CO2 and converting solar energy into chemical energy, the bulb is developing buds and storing resources for next year’s flowers. It is important to feed, and water, and encourage the bulbs to retain their green, photosynthesizing leaves for as long as possible. Dead-heading after bloom routes more energy into the bulb instead-of the energy demanding seeds. Cut off only the seed heads and dead flowers, leave as much green stalk (photosynthetic potential) as possible. Remember this when cutting flowers to bring indoors. Taking flowers from bunches of Daffodils is beneficial to the bulb as long as you leave plenty of foliage.
Bulbs in a lawn give your garden an early playful appearance of a wild meadow. They bloom and fade long before you’ll ever need to mow. Snow Crocus, Scilla and Chionodoxa are all excellent candidates for lawn bulbs. Plant in wide drifts of like colors.
Woodland plantings use bulbs that “naturalize” (adapt and spread) in open shade. Bulbs add a cheerful display before many woodland perennials will be in bloom. Rock-garden and “woodland” type Narcissus, Ice Follies daffodil, Anemone, Chionodoxa, Crocus and Scilla planted along with ostrich and lady fern, coral bells, bleeding heart, forget-me-nots, Brunnera, violets, sweet woodruff and Hosta make a beautiful woodland planting. Bulbs are incredibly easy and infinitely satisfying and should always be included in “wildflower” gardens.
Planting in pots and barrels outdoors can be tricky. Make sure you provide for ample drainage. In a large wine barrel, plant bulbs as you would in the garden and, if possible, keep the barrel out of the sun for the winter to avoid thawing / freezing cycles that can kill any roots; the larger the container the better your chances for success. In smaller wooden pots it seems to work well to bury the entire container under a foot or more of pine needles in a shady spot.
Autumn Crocus and Colchicum are hardy bulbs that bloom in the fall. In spring, they produce only leaves that work to collect and store energy as the buds develop. Autumn Crocus then go dormant for most of the summer. In fall, the bulbs produce only flowers when the rest of the garden is going to sleep. If purchased in fall, the bulbs will bloom whether planted or just sitting on the counter. If planted indoors it is nice to grow a little grass in the pot to compliment the beautiful pink flowers. After blooming indoors, plant the bulb into the garden to be enjoyed for decades to come.
Many of the hardy outdoor bulb varieties can be “forced”, with chilling, to bloom indoors. Hyacinths are probably the most widely forced bulbs because of their sweet fragrance, compact size and ease. Hyacinths (and Crocus) bulbs can be planted in small pots, just below the soil surface and kept moist in a cool, dark room, pantry, heated garage, or closet. Neither is very picky. When the leaves reach about 2” (8-12 weeks) bring them out into the sun. Anemone, Grape Hyacinth, Scilla, Chionodoxa, Daffodils and Tulips can all also be forced but require very specific temperatures and chilling periods.
There are many bulbs that bloom well inside the house without forcing. Amaryllis and paperwhite bulbs will bloom profusely without any chilling. When making a purchase of ANY bulb, remember, the larger the bulb, the more blooms you’ll enjoy.
Look at the pictures on the bins for planting ideas when you’re making your bulb selections.
When bulbs have increased in a location beyond their means (this is evident when there is more and more foliage with fewer flowers) it is time to divide. Late spring, as the foliage is just beginning to fade, is a good time to dig up the bulbs, pull them apart and replant them in new locations with the foliage intact. This may be done in fall as well but it is difficult to find the bulbs without destroying them.
