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Growing Bulbs for a Well-Rounded Garden

We're seed retailers. So what's the deal with us writing an article on growing bulbs? Well, let's see. In the past year, we've covered everything from lawn flamingos and bathtub Marys to attracting birds and bats, so why not? Every balanced garden includes plants grown from seeds, bulbs, cuttings, and saplings so we're not threatened by tulips and daffodils, folks. There's enough love to go around. 

A brief history of ornamental bulb plants

There's an interesting story behind tulips, the plant we most often associate with bulbs. Trade routes brought these Himalayan natives to the Ottoman Empire, where they became a status symbol. Later, 16th-century French-born botanist Charles de l'Ecluse (1526-1609) introduced tulips to the Netherlands where, by the 1630s century, they became so coveted that they became an important commodity. You'll find as much historical data on tulips from investment experts as you will from garden clubs and bulb producers. Last summer, in an article titled "What do Bitcoin and Tulip Mania Have in Common?" cryptocurrency writer Marcia Wendorf wrote this about tulips: "They were the world's first futures contracts, making the Dutch the inventors of modern finance." 

Demand fueled thievery, which, in turn, fed a black market, and "tulip mania" — pretty much the official title of this phenomenon — took root. According to the Dutch bulb distributer Fluwel, players in the tulip underground planted bulbs (underground!) to propagate them, prodding new mutations, hybrids, and varieties.

"A single tulip sold was worth as much as a canalside house." — "Tulip Mania", Fluwel

A mosaic virus was responsible for some spectacular mutations and bulbs from these plants, turning some varieties into the hottest commodities. The legendary striped Semper Augustus tulip is a prime example. Investors dumped everything they had into these new bulbs, but — whoopsie — they didn't easily propagate if they did at all. This became one of the triggers of what many historians call the first burst market bubble. Legal battles over debts to bulb suppliers clogged the courts to the point at which cases were flat-out rejected or debts forgiven to preserve the economy.

According to Fluwal, "Although the tulip trade was often mocked by poets and comedians, prices would stabilize and eventually tulips' cultivation became a respectable industry," but bulb collectors didn't learn their lesson. Exactly a century later, hyacinths kicked off another bubble, and in subsequent centuries other bulb plants caused speculative frenzies. 

How bulb propagation differs from seed-grown plants

Okay, that headline's a bit misleading. Bulb species propagate sexually (via pollination and seed dispersal) and asexually (developing "bulblets" off the primary bulb). So technically, flowers like tulips and daffodils can be grown from seed, but it can take several years for the plants to bloom. And when they do, their flowers aren't likely to look like the parent species. That's because many cultivars are hybrids. Bulbs, on the other hand, are essentially clones of their "mother" plant. 

Bulbs, rhizomes, tubers, and corms store the "food" a plant needs for early, accelerated growth. Bulbs, in particular, are the plant equivalent of nitro booster canisters found in racecars. Most other perennials store energy in their roots but are more reliant on generating their "food" from sunlight and warm soil microcosms before spring regrowth really takes off, which is especially challenging early in the season with shorter daylight periods, cool or even frosty soil, and overcast skies. 

Bulbs aren't always perennial

Some bulb species, once they reach maturity, go downhill in subsequent seasons. Hybridized tulips fall under this category, which is why you'll treat store-bought bulbs as annuals, replacing them every year or two. Species tulips (also called botanical tulips), on the other hand, hold up over several seasons. They're generally smaller and more delicate than cultivated tulips and are closest to the wild specimens found in the Himalaya and surrounding regions. 

Long-lived bulb species include narcissus (daffodils), crocus, and Darwin hybrid tulips. Some bulbs multiply vigorously, reproducing in colony-like fashion so it's tough to tell which are the originals. Snowdrops are among them. 

When to plant bulbs

Don't freak out if you blew off bulb planting last fall. There are plenty of species that prefer to be planted in the spring, and if you have a stash of fall bulbs you might as well stick 'em in the ground with a song and a prayer rather than wait until the time's right. Even under optimal conditions, bulbs can deteriorate in storage. 

Spring-blooming bulbs

In areas where the ground freezes, plant them about six weeks before your area's first hard frost date. (Here's a handy frost date chart for the Midwest). If you live in a mild-winter zone, wait until the nighttime temperatures drop to or below 50°F. Ideally, bulbs need to grow a root system before winter sets in so they'll be ready to take off when the soil warms in early spring. 

Here are species requiring fall planting: 

  • Allium (including onions, shallots, and garlic)
  • Crocus
  • Starflower
  • Bearded iris
  • Hyacinth
  • Grape hyacinth
  • Daffodil/narcissus
  • Snowdrop
  • Tulip
  • Scilla

Summer and fall blooming bulbs

These popular bulbs bloom later in the season, and they're best planted in the spring after your last predicted frost: 

  • Gladiolus
  • Most lilies
  • Anemone
  • Ranunculus
  • Freesia (some varieties prefer fall)
  • Crocosmia

Bulbs are easy to grow

There are species that prefer shade, those that love full sun, and bulb plants that bloom in the beginning, middle, or end of the growing season. But as long as they're planted in well-drained soil they're resilient and reasonably adaptable, which means you'd have to have a pretty black thumb to mess up a bulb garden — unless you're lazy. They do require seasonal attention to keep them healthy, and since bulbs are far more expensive than seeds, you can save a lot of money by looking after your bulby babies.

gardener preparing bulbs

Planning a bulb garden

Pay special attention to bloom times, average heights, and sun and shade requirements. Most bulbs require at least six hours of sun, which will still be low on the horizon. Select your favorite bulb companion plants to hide fading leaves once your bulbs peak, since their leaves help replenish their stores until they're completely brown.

If you're plotting out a new perennial garden save some room to interplant annuals and bulbs. Take into consideration your perennial's size potential and root structure. Deciduous trees and shrubs might not leaf out until after your spring bulbs have dropped their blooms, so that opens up your options for bulb beds. 

Patio gardeners can grow bulbs in containers, which is an especially good idea in warm-winter zones. Bulbs appreciate a chilly period, so storing pots containing dormant bulbs in a cool shed, cellar, or garage can increase their vigor during bloom time. 

Planting and fertilizing bulbs

When you're starting new beds, amend the soil with aged compost, especially if you have fast-draining, gravelly or sandy soil. Got clay? Loosen the soil below the desired planting depth and add a bit of sand with your compost. Mix a granulated 5-3-5 (nitrogen-phosphorus-potassium), or 10-10-10 with a couple of handfuls of phosphorus-rich bonemeal. Add a layer of loose, unfertilized compost and soil to serve as a buffer. Bulbs send roots out of the basal plate on their bottoms, so making the fertilizer available where they need it prevents waste, but direct contact between fertilizer and the bulbs can cause problems.  

Quick tip: Dig a hole three times as deep as the bulb's height, measured from basal disk to pointed tip. You might want to add an inch or two of depth to loosen and amend the soil and add a buffer between the bulb and concentrated fertilizer. Remember to keep the pointy end up! 

Most gardeners don't bother feeding short-lived "annual" bulbs after they're planted, but perennials will need to replenish their stores. Once the leaves have emerged, give them a half-strength liquid feeding. Bonemeal takes a while to break down, so you can stick with the 10-10-10 formula the first year but you might want to switch to a bulb-specific 5-3-5 formula after that.

The University of Illinois Extension program advises gardeners to skip feedings after flowering to help fend off bulb rot. Other bulb nerds encourage post-bloom feeding, though, so if you want to give yourself the extra chore, be sure to dilute the solution by half. 

Dividing and storing bulbs

After a couple of years, your bulb plants will get crowded as they develop new bulbs ("increases") and plants. The best time to dig up and separate bulbs is when about 75% to 85% of their leaves have turned brown.

Use a digging fork or spade to carefully break a wide circle around and under the bulbs. Gently lift the soil and use your hands to loosen and remove as much dirt and debris as possible. Some bulbs require washing before storage, while others are too delicate and are best left a little on the messy side.

Ditch any diseased or spongy bulbs, and either replant healthy increases immediately in their new spots or leave them to dry at room temperature in a dry, well-ventilated location. Breck's, a popular source for bulbs, recommends spreading daffodil bulbs (middle of the road in terms of care) indoors on a few layers of newspaper for a week to 10 days. Once they're "cured," place them in mesh onion bags and store them where it's cool and dry, with good airflow. Some bulbs, like callas, only require about three days, while others such as gladiolus and other large-bulbed species may need three weeks to cure. Look up recommendations for each species to make sure you get the humidity, curing time, and temperatures right. 

We've got ulterior motives

Bulbs help newbies learn gardening basics and reward them with high success rates, so it's in our best interest to push them on our customers even if we don't sell them ourselves. Variety enhances your garden and enriches your interaction with it, increasing the odds that you'll stay hooked. We'll continue to enable gardeners through our blog and excellent customer support, and we welcome you to hit us up for tips on growing a diverse landscape. In the meantime, dig deeper into bulb gardening with Bulbs: Practical Advice and the Science Behind It by Jim Hole and Lois Hole!

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