Crop summary: Skirret, Sium sisarum

We've grown skirret in our yard since the first year we moved here. I obtained seed from the National Germplasm Repository for research purposes, and direct seeded them March or April 2006. Several plants grew up just fine, and betweeen propagating those vegetatively and volunteers appearing from seed, we've expanded to two or three dozen plants in the yard.

I haven't paid close attention to plant size, so don't take this as gospel. But first year plants reach maybe 18-24" tall and 18" wide. Presumably plants growing from seed attain a smaller size than those with the headstart of vegetative propagation. Our two or three year old plants grow much larger; I measured a two year plant just now and it's grown to 3' tall and 2.5' wide. If I recall correctly, a three year old plant last year in almost full sun reached 5' or 6' tall by the time it flowered in July. In that case, the height proved problematic--the plant put on much of its growth in the dry weeks of June, receiving neither rain nor irrigation. When we started irrigating with sprinklers in early July, the weight of the water bent the tall plant over, making it sprawl into the path. So this year we'll either irrigate sooner so the plants grow accustomed to the practice, or we'll stake up the tallest plants, especially those unsupported by other surrounding vegetation.

Skirret makes the typical carrot family flowers, which provide food for beneficial insects such as predatory wasps. Last year the plants in our yard began blooming July 4th; in 2007 they began July 11th. I didn't keep track of how long the bloom season lasted. It produces copious quantities of seed. I haven't seen any references to people or chickens eating the seeds, but I'd like to experiment with them, since they could provide substantial calories.

Right now we grow skirret to eat the octopus like clump of individual fingerlike roots, each up to 12" long and up to 3/4" thick, all branching out from the crown. We dig up the clump, shake or wash off a lot of the dirt, and cut off the roots from the underside. Then we divide and replant the crown, which has made 6-18 vegetative shoots which can be individually planted out, or just replanted as a group. Skirret also self seeds itself very well; it has begun volunteering itself throughout our yard near parent plants. If you want to propagate the plant more quickly, you could divide after the first year of growth and either eat the roots or replant them with the crown divisions to give the divided plants faster growth the next season. I don't remember whether our first year plants from seed or divisions usually flower the first year or not until the second, so I'm not sure how quickly you'll get seed production.

The pictures above came from first or maybe second year plants I took the pictures several years ago so I don't remember much detail, such as whether I had already removed any of the roots from the clump. Most of the plants I harvest these days have 5x to 10x that many roots attached.

We usually steam the roots for 10 minutes or so which sweetens them up even more than in their raw state, but they make a fine raw snack too. They taste like a carrot/parsnip combination, and leave me feeling well fed and full. Most descriptions of the root mention a woody core at the center of the root, but we find only our thinner, smaller roots have the woody core. We rarely mix skirret into other dishes, but if we do, we just use the fatter roots without any woody core, and save the thinner roots for eating on their own, by stripping the flesh from the woody core with our teeth. Usually we just steam a big mess of fat and thin roots and eat them as a side dish.

Plants grown for one year make smaller and fewer roots with higher likelihood of the woody core. So we usually grow them for two or three years before harvesting. I realized this year that skirret would probably work well grown along with cinnamon vines (Dioscorea batatas) which also works best if you let it grow for 2-3 years before digging and harvesting the roots. Dioscorea batatas shoots emerge very late in spring, which would give skirret a chance to use available sunlight for a few months before receiving light shade from the cinnamon vine growing up the bamboo poles we normally provide.

Our skirret has thrived with minimum care; it seems to handle drought to moderate moisture, and full sun to heavy shade just fine. I haven't paid close enough attention to harvests of roots in different conditions to know whether better growing conditions results in more or better (less woody) roots. Nor have I weighed any of my harvests to calculate productivity per square foot per year. I'll probably do some of that this fall.

Skirret stores in the ground through the winter. We harvest skirret as needed in its dormant season from fall to early spring, up until the new shoots get about 6" inches tall. I just noticed a description at Jonathan Bate's Permaculture Nursery saying "Roots can be detached and eaten fresh. Root harvest will not harm the plant." I read that to mean you could detach roots during the growing season by digging at the clump from the side and eat them on an ongoing basis. But when I tried it a few days ago, it yielded pithy soft roots which had no flavor and lots of fiber. I might try more such experiments later this summer and into the fall to find out when you can start harvesting decent roots.

We tried growing skirret with the chickens, protecting them for the first year in a cage, then digging out half the clump to eat while leaving half the clump in the ground. I thought perhaps the half left in the ground would grow vigorously enough to overcome chicken abuse. But the chickens won. We have chickens free-ranging our entire back yard all the time; this method would probably work better in a rotating paddock chicken setup, where plants would have a solid 3 weeks to grow before the chickens returned. I might try the experiment again with even better established plants.

As a tall clumping plant with plenty of foliage up high, skirret seems to grow fine with shorter plants all around it, such as peppermint or annual weeds. It also holds it own for us amongst other tall perennials such as fennel, lemon balm, and french sorrel.

We sell seeds mail order or in person, and (when available) sell starts for pickup only. See Discount Permaculture for more info.

As always, Plants for a Future has more helpful information on skirret.