Bulb Planting Basics


Bulb Basics

Spring blooming bulbs are a wonderful addition to your gardens and landscape. They are easy to plant and care for. Here are some basic tips:

When do I plant bulbs?

Spring blooming bulbs are planted in the fall, anytime from September until the ground freezes. The ideal time to plant them is in late October, after you have begun cutting back your perennials so that you can see the spaces left between the plants. If you buy your bulbs early to get the best selection, store them in the garage or shed- a cool, dark place- until you are ready to plant them.

How late can I plant my bulbs?

As soon as you plant your bulbs they begin to grow roots so it is best to do so while the ground is still a bit warm, in October. However, if you forget, they can be planted in November and December. We have even been seen planting bulbs in a warm spell in early January! It’s best to get them into the ground, no matter how late.

How deep do I plant bulbs?

Plant your bulb twice as deep as the bulb itself.

How far apart do I plant bulbs?

All bulbs come with instructions about spacing. We tend to not measure; instead we place them in “drifts” or groupings. Larger bulbs can be planted in groupings of three. Tiny bulbs are often planted in groupings of 7 or 11 bulbs. The goal is to make them look natural when they come up, not rigidly spaced out in rows. See our handout on this subject, “You Can Never Have Too Many Spring Bulbs”.

How do I prepare the soil?

If you are planting bulbs into an already established bed, just push aside the mulch, dig a hole with a sturdy trowel, add some organic fertilizer (Coast of Maine Fish Bone Meal or North Country Organics Pro Gro), and plant the bulb. If you are breaking new ground for your bulbs, remove the sod or weeds and compost it. Turn over the soil so it is loose; remove the rocks. Smooth out the soil; plant the bulbs as described above.

Which end is up?

When we talk about planting “bulbs” we are actually talking about true bulbs as well as other underground storage organs such as rhizomes or corms. True bulbs such as daffodils and tulips, have a basal plate where the roots come out and a tip at the top where the shoots come out. The basal plate goes down. Don’t worry. If you plant your bulbs upside down or sideways the shoots will find their way up to the light.

What if the leaves start to grow in the fall? Will that hurt the bulbs?

No. Some bulbs such as grape hyacinths actually produce leaves in the fall and they live through the winter. In a warm fall or winter, sometimes the leaves of the earlier bulbs will stick their noses up through the ground. You can cover them with cut evergreen branches in the winter to keep them from growing too large. Take the branches away in late February or March- many bulbs bloom early!

How do I care for the bulbs in the spring?

The most important thing to know is that the leaves of your bulbs produce food which is then stored in the bulb for next year’s flowers. As soon as the leaves emerge, you should feed your bulbs. This is easy to do because you will also be feeding your gardens in the spring as well. We use a mixture of Pro Gro organic fertilizer and Coast of Maine compost. Mix it in a wheelbarrow and sprinkle it around your bulbs. The longer the leaves grow, the more food is made for next year’s flowers. Long lived bulbs such as daffodils have notoriously long lived leaves- five or six weeks or more. Shorter lived bulbs such as tulips have leaves that start to die off within a week or two after flowering. To prolong the life of tulips and other bulbs with short-lived foliage, feed them a second time with a sprinkling of Pro Gro organic fertilizer as soon as they have finished flowering.

Can I cut off the leaves of my bulbs when they are still green if they are in the way in my spring garden?

No, never cut off the green leaves of your bulbs as that will weaken them and they may not bloom the following year. The leaves should be encouraged to grow for as long as possible. Plant the bulbs in between perennials. As the perennials grow they will hide the ripening leaves.

Do I ever need to divide my bulbs?

Daffodils are very long lived. Each bulb forms many bulblets and each bulblet becomes a bulb. After 5-6 years, you may find your clumps of daffodils have lots of leaves and not as many flowers. This is because the clump needs dividing. The ideal time to do this is in late spring, after flowering but before the leaves go dormant. Dig up the entire clump and place it on a tarp. Separate the bulbs. Plant some of them back in the same spot (use this chance to amend the soil again with compost and Pro Gro). You will end up with lots of extra bulbs that you can plant in new places!

I have big green leaves but no flowers on my tulips. What should I do?

After a few years, especially if you don’t feed your tulip bulbs, they peter out. If you see big leaves and not flowers, dig up the bulb and compost it. Plant fresh tulips next fall.

Can I grow bulbs in the house for winter flowers?

Hardy bulbs need a chilling period in order to grow roots and form their flowers. This chill period ranges from 10 to 14 weeks. If you want to grow bulbs in the house for winter flowers you should pot them up in the fall and keep them cool (34-45 degrees) for the proper chill period and then bring them into the house. See our handout about this subject,“Bulb Forcing”.

I have wet, clay soil. Can I still grow bulbs?

Almost all bulbs must have good drainage. If you plant them in poorly drained soil they will rot. The exception is Camassia bulbs. They do fine in wet soil and are one of our only native American bulbs.

How do I stop animals from eating or digging up my bulbs?

Voles are the underground enemies of bulbs. Use Repellex systemic when planting bulbs and plant them early to get the roots growing. This product is only absorbed into the bulbs when they are actively growing. I you plant your bulbs just before the ground freezes it won’t work. Sprinkle Repellex granular on the surface of the soil to repel voles as the systemic takes 2-3 weeks to become effective. Daffodils, snowdrops, summer snowflakes, and Alliums are not bothered by voles. Squirrels will dig up bulbs when they see the ground has been disturbed. Lay down chicken wire and pin it down with landscape fabric pins to stop them from digging. You can also spray the soil with Hot Pepper Wax. Deer eat many bulbs in the spring. Reapply Repellex Systemic in the spring as soon as the foliage emerges and this will protect them from being eaten by deer for three months. Or, spray the foliage and flower buds with Deer Stopper and apply Deer Scram every three weeks.

 In an effort to provide horticultural information, these educational documents are written by Nancy DuBrule-Clemente and are the property of Natureworks Horticultural Services, LLC.  You are granted permission to print/photocopy this educational information free of charge as long as you clearly show that these are Natureworks documents.