November 7, 2022

The one animal I will never, ever give the chance to ruin my tulip crop is… drum roll… VOLES.

We took no chances with voles this fall, completely mice- and vole-proofing our tulip bulb planting. There is only one material that can stand up to the job, in my opinion, and that is hardware cloth with 1/2” holes.

How to identify voles

It’s important to understand whether you have a vole issue before you plant your tulip crop. I would recommend vole-proofing your tulip bulbs even if you think you don’t have a vole problem… you never know who might move in under 6 inches of snow cover in January and February (don’t ask me how I know!)

Voles are related to field mice. They look like mice but have shorter, 1/2”-long tails (I easily identify them by tail length). They are mostly vegetarian and quickly reproduce. If you see one vole, you can be sure there are at least 25-200 more living close by, a bunch of which may be pregnant with the next generation of tulip bulb destroyers.

You’ll know you have voles when:

You actually see voles (See a mouse thing? Look for the short tail).
You see “runs” they have created through grass and across the top of your soil (see photo below). The runs lead to different entrances to their burrows. Only voles leave these runs.

Why are voles an issue for tulips?

Voles never hibernate, which means they spend the entire winter (usually covered by snow) searching for, and eating, vegetation. For whatever reason, they love tulip bulbs, most likely because they provide a healthy source of fat and don’t have any off-odors/flavors like alliums do. Voles will create tunnels underneath the soil surface straight to your tulip bulb patch, set up a cozy nest for themselves, and eat whatever they need to survive all winter when there’s nothing else around.

When you don’t protect your tulips from voles, you basically spent hundreds (perhaps thousands, if you’re a cut flower farmer) of dollars on a nutritious, delicious buffet just for voles to feed on all winter. How generous we gardeners are!

How to completely vole-proof your tulip patch

You’ll need to wrap the entire patch in hardware cloth from top to bottom, to prevent them from getting in.

Below are steps to how we do it, from a cut flower production perspective. We plant thousands of tulip bulbs every fall, in long rows. This hardware cloth concept can easily be adapted to a landscaping/backyard gardening application by fashioning small “cages” out of the hardware cloth.

Steps for Creating a Hardware Cloth Barrier to Keep Out Voles (photos below)

Dig your tulip trench 6 inches deep. This is your typical bulb trench you would normally dig to plant tulip bulbs.
Pre-cut a piece of hardware cloth to the length of your trench, plus 2 feet extra on each end. I suggest pre-cutting so you’re not having a roll a heavy piece of hardware cloth over your trench, knocking freshly dug soil back into the trench.
Helpful Note: Use hardware cloth that has an appropriate width so it will stick up a few inches above the planting once the soil is back-filled. For instance, our trench was 18” wide and we used 36” wide hardware cloth.
Line your trench with the piece of hardware cloth. Step along the sides of the hardware cloth inside the trench so it lays flat.
Important Note: We highly recommend you use hardware cloth that has 1/2” square holes, like the one linked here. Do NOT use chicken wire/poultry netting. Surprisingly enough, voles will get through 1” round holes in chicken wire and all of this effort will be for nothing if they get in. I’ve seen some people double up layers of chicken wire, but I wouldn’t even risk that. Spend a little more money on the hardware cloth to ensure the voles will NEVER find a way in.
Add 1/2”-1” of soil on top of the hardware cloth inside the trench. There may be spots in your trench where the ground is uneven and the hardware cloth has a layer of air space between it and the ground. When this happens, fill the air spaces in with soil. We’re adding this soil to the top of the hardware cloth so the tulips have soil to root in.
Plant your tulips how you normally would. We lay ours directly next to each other throughout the entire trench (FYI, tulips for cut flower production are planted much closer together than landscape tulips because they are dug up and replaced every season). Cover your tulips with compost and native soil to a depth of 4-6 inches.
At this point, your tulips will be completely covered and planted, with a layer of hardware cloth lining underneath them and up the sides of your trench. A few inches of hardware cloth should be sticking out above the soil at each side of the trench.
Cover the top of your trench with more hardware cloth. We did this by creating a “hoop” with the top piece of hardware cloth and zip tying it to the side edges of the bottom piece. I recommend using skinny zip ties for this; thicker zip ties are hard to get tight. The ends were a bit tricky to tie together because of the curve, but we managed by cutting into the corners a bit and pressing down really hard. This definitely works best with two people.
Helpful Thought: I’ve seen people skip the top piece, which I don’t understand, because voles can not only burrow underground… they can also CLIMB.

Thoughts on raised beds

You can also prevent voles from eating your tulip bulbs by planting the bulbs in raised beds. By “raised beds” I mean garden beds that have been constructed with wood, typically 2x12’s. Keep in mind that the beds must still be lined on the bottom with hardware cloth, but the nice part about the raised beds is you’re not having to dig trenches every year. I would still err on the side of covering the top of the raised beds with hardware cloth, but I am also someone who has suffered major vole trauma so I’m not willing to take any chances.

I hope this has been helpful in showing you how to 100% vole proof your tulip bulb plantings…. and perhaps even shed some light on why they’ve gone “missing” over winter!

peace, love & spring flowers,

Fran Parrish