How to plant bulbs this fall for a beautiful spring garden

Gardens inherently occupy a fourth dimension. Plants respond directly to the passage of time: each day, each season, each year. Gardeners also must become temporal creatures, understanding that planting must precede enjoying the plant.

The time spans vary. A sweet basil planted in late spring rewards almost immediately, but it is spent by late summer. A shade tree will take several years to fulfill its promise but will last for generations.

In the balancing act of waiting and being rewarded, no class of plants provides such a short wait for so much long-term pleasure as spring bulbs. They are generally planted between September and November and can bloom from February to June. They are thus not confined strictly to spring, though the bulk of their display is from March to May — the most dynamic period of the year, when the garden shifts from mostly bare to luxuriantly lush.

The “bulb” comes in many guises — true bulbs, corms, rhizomes and tubers — but the point is that the dormant organ in your hand has already stored the energy it needs to grow and flower. This means even folks who don’t consider themselves green-thumbed gardeners will have success with bulbs if they observe a few basic rules.

The succession of bulbs in the first few months of the year goes (loosely) like this: winter aconites, snowdrops, bulbous iris, crocus, early daffodils, scilla, glory-of-the-snow, species tulips, snowflakes, muscari, hyacinths, midseason daffodils, main-season tulips, late-season daffodils, camassias and alliums.

The sequence can and does change with the weather. In mild winters, now no longer uncommon, aconites, snowdrops and early daffodils can appear two to four weeks earlier than in previous years. At the other end of the season, hot days in late April can blast tulips and daffodils, shortening their display.

[Planting bulbs offers a bit of hope for better things to come]

It is best not to fret about that; a wide array of spring bulbs blooming over several weeks will even out the vagaries of the weather and provide a season of welcoming cheer. They are supremely versatile, with miniature bulbs suited to the tiniest spaces, including pots. Planted by the hundreds, bulbs can hold an entire area of landscape, then recede to let other plants step onto the stage.

Spring bulbs bring the garden alive while deciduous ground covers and woody plants are just waking up. This role has taken on a greater meaning in recent years, as gardeners have moved to plant more perennials and grasses geared to perform in summer, fall and even winter (with their dried top growth). Spring bulbs are also natural companions to these grasses and perennials (and deciduous ground covers), because the bulbs can be tucked in among them without competing for space, given their different life cycles.

Where to get bulbs

Traditional bulb catalogues still abound, most with long-standing connections to growers and shippers in the Netherlands. They have also moved online. Or you can buy bulbs from other online retailers (some sourced from those same traditional catalogues), although prices may be no bargain, and varieties may be sorely limited.

When comparison shopping, look at not only the named variety of bulb but also its size. This is measured at its circumference and given in centimeters. Larger bulbs tend to have more flowering stems.

[The unexpected elegance of the daffodil]

Mass merchandisers are among the first to offer spring bulbs — and they also have some of the best prices — but be careful. Bulbs are best stored in cool, airy places and will deteriorate in adverse conditions, so it is best to buy bulbs soon after they appear on shelves, then get them in the ground or store them yourself. Garden centers tend to have a broader selection of bulbs and know (hopefully) how to handle them.

One way to reduce the per-unit cost of a bulb is to buy in bulk, and some catalogues offer quasi-wholesale prices with a minimum order size. Because most folks don’t plant anywhere near enough for optimal effect and pleasure, these lower-priced bulbs are a good way to fix that. In addition, bulb traders have turned to offering themed collections of unnamed varieties to the general consumer as a way of reaching novice gardeners and making bulk sales at low per-bulb cost.

Another way to save money is to wait until late in the market season for bulbs to go on sale, either from bricks-and-mortar outlets or online retailers. The downside is that availability will be reduced, and the stock may be compromised, particularly with bulbs that have been sitting on shelves for weeks.

When to plant

Bulbs are living things programmed to break dormancy and start growing once they are in the ground and the soil is cool and moist. They need somewhere cool and breezy to await planting. The best place to store spring bulbs is in the refrigerator (not the freezer). Don’t store them with apples or other fruit, which give off gas and can mess with bulbs’ flowering abilities. Check them periodically, and remove any bulb showing mold or softness.

[It’s tulip-planting time]

If you are into gardening, consider getting a cheap fridge to store bulbs, seeds and cut flowers. An old-fashioned type that is not frost-free is optimal, because it has more humidity. Set the fridge on the warmer side to avoid unintentional freezing.

Planted bulbs need a minimum number of weeks growing at cold temperatures to bloom successfully. This requirement differs by variety, but it is typically at least 12 weeks. The earlier a variety flowers in the spring, the sooner it should be in the ground. Snowdrop bulbs are particularly perishable and should be planted as soon as possible, preferably in September.

Tulip bulbs can be planted last, provided they have been properly stored. When the ground freezes, bulb-planting comes to a crashing halt, so don’t delay for too long.

How to plant

Select an appropriate site, ideally in an area of light shade or a sunny site. Bulbs are effective woodland plants, but if they are placed too deeply within an area of trees, the foliage will not get enough sunlight to flower well in successive years.

Most bulb species are native to dry, rocky landscapes and dislike heavy clay soil that stays too wet, especially during summer dormancy. Irrigation systems are no friend of the bulb.

The standard advice is to plant a bulb at a depth twice its height, so a two-inch bulb would need a four-inch hole. Please don’t whip out a tape measure with every bulb; just get the tops buried. However, the deeper you can plant a bulb, the safer it is from squirrels. I like to plant tulip bulbs at six or seven inches.

[These miniature flowers are perfect for small spaces and budgets]

Bulbs don’t have to be planted upright — they will figure out which way is up — although planting them with the nose up and the roots down makes the gardener feel better and may save the plant some growth effort. If you are planting corms that are hard to orient visually, place them on their side.

Having the right tool makes all the difference. Avoid cheap, weak-necked trowels. A quality trowel is fine for planting small bulbs, but for larger ones, such as daffodils, tulips and alliums, you will need at least a handheld bulb-planter. (And, I suggest, a cushioned kneeler.) A long-handled bulb-planter uses the legs, which is much more efficient, and your strength will be amplified if you have sturdy boots and strong gloves. It helps to have a partner on the ground, placing the bulbs. If you have compacted soil, heavy clay or soil embedded with stones, try a pick-like mattock. You can buy a bulb-planting auger, which attaches to a cordless drill, but this works best in improved, loamy soil. It can be halting and wrist-jarring in soil full of buried stones or tree roots.

If you are planting in a bed that has no other existing plants, such as an annual flower bed or a part of the vegetable garden, you can excavate an entire trench with a shovel. This is an efficient way of planting dozens of bulbs, which can be pulled after flowering or relocated as the leaves begin to wither. I grow tulips this way, then replace them with dahlias in May.

One approach is to increase existing drifts of such plants as daffodils, crocuses and snowdrops each fall. But you need to know where the current bulbs are located, because the telltale foliage will be long gone by autumn. Before the bulbs recede in late spring, mark the edge of the colony with a thin bamboo cane pushed well into the ground. You can also take photographs to help locate bulbs.

Specially formulated fertilizer is useful for bulbs forced in pots (after chilling), but is generally not as important for those in the garden. If you use it, make sure it is not in direct contact with the bulbs, and avoid high-nitrogen feeds.

Wildlife can be a problem. Squirrels are drawn to disturbed soil and are partial to tulip and crocus bulbs. You can place wire netting (hardware cloth) or burlap over planted areas, hidden by mulch, but don’t forget to remove it before the stems emerge. Voles burrow underground and may eat your bulbs without you knowing it (until spring). If you have a problem with voles, one tactic is to put a handful of pea gravel around the bulb when you plant it. Deer also have a taste for bulbs, especially tulips. If you cannot exclude deer, plant daffodils, chionodoxa and alliums.

If you live in U.S. Agriculture Department Plant Hardiness Zone 8 or higher, you may need to select bulb varieties with a low winter chilling requirement or purchase bulbs that have been precooled. Check with your county’s horticultural extension agent.

Whatever you do, hurry. Fall is here, and the quality of your spring rests on your industry over the next few weekends.

Lead and icon illustrations by Jeannie Phan.