Bulb 101

Bulbs are some of the easiest plants to grow, so easy that the motto for them is “Dig. Drop. Done.”

Bulbs Types

  • Fall Bulbs, sometimes known as Spring Bulbs, are bulbs that are planted in the fall and bloom in the spring. These bulbs require a cooling period in order to bloom. Popular varieties of Fall Bulbs include Tulips, Daffodils and Hyacinths. Most Fall Bulbs are considered perennials.
  • Summer Bulbs are bulbs that are planted in spring and bloom in summer. These bulbs do not require a cooling period in order to bloom. Popular varieties of Summer Bulbs include Gladiolas, Dahlias, Caladiums and Elephant Ears. Many summer bulbs are frost sensitive and need to be dug up in the fall if you want to keep them for future years.
  • Vegetable Bulbs (or tubers), like potatoes, onion, garlic and asparagus are ideally planted in spring to harvest in late summer or fall, but can (depending on average winter temperatures) be planted in the fall for a spring harvest.

There is some overlap between the categories, bulbs like Persian Buttercups, Spider Lilies and Irises, which can be planted in either spring or fall.

Selecting Your Bulbs

When it comes to selecting bulbs, the firmest bulbs are the best choice. If a bulb feels squishy or soft, it has most likely started to rot and should be avoided. There’s no need to worry if a layer of gray mold has formed on the bulb, the bulb is still healthy and the mold can be lightly brushed off.

Packaged bulbs will have all the information you need to know about the bulb, including how tall it gets, how deep to plant it, light requirements and any special features (like if it’s deer resistant, pollinator friendly or fragrant).

Storage

Prior to planting, bulbs should be kept in a cool, dry location. Keeping bulbs dry prevents them from rotting and keeping them cool keeps them from sprouting before they are planted, which can stunt their growth.

If the bulbs will be stored for a long period of time, check them regularly to ensure they haven’t begun to rot. As soon as you notice any rot, throw the bulb out immediately.

Store bulbs in mesh bags, paper bags or cardboard boxes (with sawdust whenever possible). This keeps the bulbs dry and prevents the development of mold. Don’t use closed plastic containers as they can retain moisture which leads to mold.

Planning

The hardest part of planting bulbs is deciding what look you want. Bulbs can be planted individually, in rows or in clusters depending on the look you’re going for. Lay your bulbs out and play with the layout until you’re happy with the arrangement.

If you’re mixing bulbs, keep in mind the differences in height and bloom time. Taller bulbs should be planted toward the back and shorter bulbs toward the front.

  • Fall Bulb bloom times can vary, with some beginning to bloom in late winter (like Snow Drops) and some blooming later in the spring (like Daffodils). In general, bulbs that are planted deeper bloom later than bulbs planted at a more shallow depth. With a little extra planning, you can create a constant flow of spring blooms in your garden by planting different Fall Bulbs in the same area.

Location

When selecting the location where you will plant your bulbs, keep light and soil in mind.

Different bulbs need varying levels of light; Caladiums prefer full shade while Dahlias want full sun. Make sure that you pick a location with the correct levels of light for your bulbs.

All bulbs prefer moist, well-draining soil. Soil that stays too wet can cause the bulbs to rot. Mixing Lobster Compost into your soil when planting can increase drainage.

Planting

It’s important to plant bulbs at the proper depth, but that depth varies from bulb to bulb. If you plant them too deep, the bulbs may not be able to grow and if they aren’t planted deep enough they may begin growing too early. Packaged bulbs include instructions for depth but if you have bulbs without instructions the general rule of thumb is to plant bulbs 3 times deeper than the bulb is wide. A 1 inch bulb should be planted 3 inches deep, a 2 inch bulb should be planted 6 inches deep, etc.

When planting, make sure that the flat end of the bulb is facing down and the pointed end is facing the sky. If you aren’t sure or your bulb doesn’t have a strongly defined point, look for roots and plant the root side down.

Planting in Containers

Planting bulbs in containers is similar to planting in the ground, with the main difference being the container itself. Make sure you select a container that is deep enough for the deepest bulb you are planting.

When planting Fall Bulbs in containers, you can layer bulbs with different bloom times to create a continuous show of blooms.

Aftercare

Bulbs generally don’t require much care after they’ve been planted, aside from the occasional watering during dry periods.

Unless you’re cutting flowers to bring into your home, there’s no need to cut back bulbs, even after the flowers have faded. Let the stems and leaves linger to die back naturally on their own. During this time, those leaves are absorbing sunlight and turning it into energy to stimulate next year’s growth.

If you are planning on digging up bulbs and storing them to replant later, wait until they have fully died back. Allow the bulbs to dry and gently brush off any dirt, then store in a cool, dry place until you’re ready to replant them.

Fertilization

Bulbs generally don’t require much fertilization, one application of a low level fertilizer like Bulb Tone at planting and then once a year in spring thereafter is usually all they need.

Pests

Bulbs are generally pest free, but some varieties are more prone to falling victim to hungry deer, rabbits, squirrels and voles. Planting deer and rabbit resistant options, like Daffodils and Snowdrops, is the easiest way to keep animals away, but repellants like Liquid Fence, Repels All and Deer Scram are an easy way to protect more tasty options like Tulips.

Mixing Permatil into your soil or using Vole Bags when planting fresh bulbs will help protect them from voles. You can also repel them (along with moles) by regularly applying MoleMax.