Bulbs Harmful animals

The Bulb That Repels Squirrels

Ill.: clipartbarn.com & flyclipart.com, montage: laidbackgardener.com

Squirrels are cute … when they’re not eating our freshly planted spring bulbs! And one way to keep them at bay is to plant bulbs of crown imperial (Fritillaria imperialis), also called imperial fritillary, nearby. Its skunky odor seems to either discourage squirrels, keeping them at a distance, or confuse them, preventing them from finding bulbs of tulips and crocuses they love to steal. In either case, you’re the winner!

It’s not just the bulbs that stink: the flowers and leaves that will sprout next spring do too. Not intensively, but still, you don’t want to plant this bulb too close to a window that you keep open in the spring or the unpleasant smell will waft in. Try keeping a distance of at least 3 feet (1 m) between your crown imperials and from any possible olfactory conflict.

Beautiful Plant, Stunning Flowers

Any squirrel-proofing that this bulb does is secondary to its beauty. No wonder Linnaeus gave it the name “imperialis!” Or that it picked up the common name of crown imperial. Many consider it to be the most beautiful of all the spring bulbs!

Crown imperial is a stunning garden plant! Photo: www.homedepot.com

It’s a big one, too. Around 30 to 40 inches (80 to 100 cm) tall: certainly, the tallest of the early spring bulbs. Its strong stalk is covered up to mid-height with smooth shiny ribbonlike green leaves, then a section of bare stem, green to purple, is visible. The stalk is then topped with a tuft of shiny green leaves, rather like a pineapple. Under this crown of leaves form large orange, red or yellow hanging bells. The effect is breathtaking!

Weird Bulb

This is what a crown imperial bulb looks like: the hole on the top is perfectly normal. Photo: iBulb.

The bulb is a large one, typically 7 to 9 inches (18 to 23 cm) in circumference, about the size of a baseball, and very odd-looking. It’s made up of swollen scales clustered tightly together. It has a basal plate with possibly a few dried roots underneath, but unlike better-known bulbs, doesn’t have a pointed tip. Instead, there’s a hole on top.

Also, there’s no papery tunic wrapped around it like a tulip or onion. Instead, its soft, fragile, creamy skin is exposed to the elements and gradually dries out over time when it’s placed on display in your local garden center. As a result, it starts to dry out and turn brown. This is one bulb that you should plant without too much delay, while its skin is still mostly cream-colored.

The crown imperial is not a cheap bulb, either. Its heaviness compared to other bulbs makes shipping pricey and the supplier needs to apply special storage methods beyond what other bulbs need. So, you’ll likely see it sold as an individual bulb, not in a 10-pack. If you have the money to do so, it looks its best in groups of 5 to 7 bulbs. For squirrel duty only, though, plant the bulbs about 4 feet (1.2 m) apart: that will keep squirrels away without costing too much. 

A Rather Demanding Bulb

There are several different cultivars on the market. Photo: www.homedepot.com

The crown imperial is not your typical easy-peasy, just-dig-a-hole-and-drop-it-in bulb, although a brief explanation seems quite typical of average bulb care: full sun, winter cold (hardiness zones 4 to 9), rich soil, good drainage, etc. But the secret to good results is that the drainage has to be not just good, but perfect. In areas where springs tend to be rather soggy, that can make things difficult. So, it will usually grow best in sandy soil, or on a slope or in a raised bed. Clay soils, which retain a lot of moisture, are really not going to do it!

I keep reading the same bit of useless advice about putting a layer of sand under the bulb “to ensure drainage.” Only someone who has good drainage would think that makes sense. If your drainage is poor, no matter how much sand you put under the bulb, the nearly impermeable soil all around won’t let excess water go anywhere; it will simply fill the sand with water. You have to make sure that the water can evacuate to somewhere else. 

Also, don’t plant the bulb upright, with the basal plate pointing down, but rather place it on its side. The top of the bulb being hollow, rainwater could accumulate inside if the bulb were upright and that would lead to rot. 

Finally, it’s a big bulb and needs an extra-deep planting hole, especially in colder climates: a good 10 inches (25 cm) deep. 

Few Predators

The crown imperial’s unpleasant odor not only keeps squirrels away at planting time, but, since leaves and flowers give off the same “fragrance,” it repels squirrels, deer, hares, groundhogs and other herbivores in the spring as well.

Scarlet lily beetle. Photo: David Nicholls, www.naturespot.org.uk

In fact, very few pests attack it. It really has only one enemy: the scarlet lily beetle (Lilioceris lilii). This bright red-orange beetle likes fritillaries as much as adores its cousins, lilies (Lilium spp.), yet in fact causes little damage to the crown imperial. It’s such an early bulb that it’s up and blooming before lily beetles begin feeding. (They seem to need a bit of warmth to stimulate their appetite.) That means the flowers are safe. Then, by the time they do begin to chow down on the bulb’s foliage, its leaves are already turning yellow, because the bulb is starting to go dormant, keeping actual harm from the beetle very low.

Well treated, a crown imperial can grow for decades in hardiness zones 4 to 9 and thus keep the squirrels away for a long, long time.

Beautiful flowers and protection against squirrels? Maybe the crown imperial is exactly the bulb you need! 

5 comments on “The Bulb That Repels Squirrels

  1. Ph Boquerat

    I discovered this flower in a Vita Sackville-West’s book!!! In french “Une aristocrate en Asie”, twelve days in english…

  2. Bob Kennett

    Well it looks as though uk grey squirrels didn’t read your article – I planted a frittilaria imperialis in the hope that it would protect my gladioli bulbs but a squirrel from the churchyard opposite my garden simply came in , stripped the leaves and ran of with the flower bud I gave chase but he skittered off and dropped the bud in the drive . I will rescue the bulb and plant in a pot with a wire cage – too stinky for the greenhouse so it’s a quiet corner away from the roses !

  3. This bulb used to be very uncommon, but even as a few simpler garden varieties became available in nurseries, they are still unpopular. I thin people just do not know what they are. the native species is rare and not very pretty.

  4. I was amused to read that putting sand or gravel under bulbs is useless. I used to garden on heavy clay and did this religiously. I guess improving the soil generally is far more effective.

    • Yes, any hole in heavy clay simply fills up with water when it rains, drainage layer or not. In raised beds (without mixing that darned clay into the added soil), allows excess water to really “leave the premises”.

Leave a Reply

Sign up for the Laidback Gardener blog and receive articles in your inbox every morning!