I'm in northern California, zone 7-8ish, but my horsetail grows in the Bear Valley, below Lake Spaulding, CA, which is around 5,000 feet elevation and buried in snow every winter. I imagine it would grow for you. Also, it seems to do better if the container is buried. My above-ground horsetail are still spindly going into their third year.

Josh

My local farm implement store has 'mud buckets' made of black livestock tank material that are around 18" deep. My local Lowe's hardware store has 32 gallon earth tone trash containers also. I am thinking about burying a container in the yard within a planting bed of flowers, so that the top edge is not visible. I just don't know how deep of a container I would need to overwinter the plants in zone 5a. Also, I do not plan on drilling any drainage holes, in order to keep the water level high in the container to prevent drying out these marginal plants. Hopefully, you can share more about the size of your buried container, it's depth and diameter, along with what you used in the container.

The in-ground Equisetum are the giant type, with half-inch dowel-sized spears. They're almost five feet tall right now, and I'm hoping they'll grow even taller. They're sprayed with a deer repellent, too...but it seems that the deer eat them anyway at the end of the summer.

An inexpensive container will work perfectly. The soil in the container in-ground is a mix of native soil, potting soil, pine and fir mulch, oak leaf mulch, charcoal, and a handful of alfalfa pellets. I fertilize frequently, almost every watering, with fish emulsion. They seem to love nitrogen, as far as I can tell.

Unless you're worried about the Equisetum invading your yard, you might consider a few drainage holes. If the water in the container were to freeze into a solid block, it would probably kill the roots. Plus, Equisetum don't need to be in standing water - they grow in moist soils quite well.

A 24 inch container might be deep enough where you wouldn't have to worry about the plant invading. So you could drill or cut holes for drainage. If I'm wrong about the depth, I'm sure someone will correct me. There are *many* folks who are wary of the Horsetail.

I'll try to remember to take some pictures of my plants tomorrow.

Josh

Below, the various stones placed around the planting to shade the soil and direct water into the container. One of my favorite plants.

My containerized Horsetail - tons of new growth, but still rather small. I like the look, though, as well as the portability.

I take pictures at the end of summer, too.

Josh

Note that at my prior house, I had horsetail growing along the shore of a small lake on my property. Now I sometimes see horsetail growing wild in the country. Where railroad tracks go under a country road, horsetail seems to like the earth banks that slope from the fields down to the train tracks.

Your note re: grow sites is correct. Horsetails love disturbed earth, slopes, drainage ditches, roadside cuts, et cetera...they like the presence of water, and the ability to spread through the soil. Plus, I think they thrive on the nutrients that are washed into those areas. Fish emulsion will do wonders for Horsetail! I'd like to know how the seaweed extract does, too.

On to business ;)
I measured my in-ground stand today...they're only about four and a half feet...give 'em two more weeks and they'll be over five feet!


_________________________________________________

Next, I have a few pictorial recommendations.
This image is of my Alaskan fern, which might be hardy in your zone, too. I think this fern has an ancient, interesting look. I'm not sure if I'll put it in the yard, or enjoy it up here on the deck. I might just stock up on several more of them next spring. These would look great with conifer plantings, at the edge of a bog perhaps.

Giant chainfern:
I wonder if your zone would be too cold for Woodwardia fimbriata? It's my personal favorite, the Giant chainfern. These ferns are perfect for the "Jurassic" garden, as I like to say. I have several - containerized, and free-roaming...(they have a tendency to "walk," and split pots in the process). They take two to three years to really establish (battling sun and snow burn), and then they jump to about four feet in frond length. If they will survive in your zone, they'd be a dramatic addition. The fern on the left is a chainfern (with new fronds unfurling, thus the delicate, droopy look), the ferns on the right are western swordferns:

Here you see another smaller chainfern, planted this spring, growing in front of a log. Eventually, it will take over this area and become the primary visual focus. My goal with ferns is to create cool, shady areas that use/hold water more efficiently for the benefit of all the plants.

Final image:
Front deck: chainfern and Alaskan fern in pots. The chainfern is due for a repotting early next spring.
(Just for reference, the big-leafed plant is my Pachira).

Josh

This is what they looked like:

June 24th, here we are at 63.5 inches.
Oh, and notice the lovely orange light and smoky cast to the air...thanks to the hundreds of wildfires burning in northern California! Terrible for the lungs, but novel otherwise.

Josh

Josh

This is my first time to go to the bog garden forum. I've
really been enjoying your conversation.

When I was an 8 year old in ancient times our family moved
from central city Indianapolis to a small town in Western Illinois. Behind the house we rented was an undeveloped
half block with a RR siding going to a casket factory about
a quarter mile away. Much horsetail rush grew there. We had never seen it before--It was called Scouring Rush. We
"Newbies" were greeted with the folklore that under each
rush clump there was a buried Indian. We spent many hours
digging but never found any graves. (It was Blackhawk war
territory) I've loved equisitum ever since.

We now live in the 14 acres left (historical easement) of an 1830 farm in Indiana with woods, creek, half acre pond,
etc. The rest of the 150 acres is residential development,
43 acre nature preserve, and some common parkland. There
is lots of equisitum down near the creek. I've hesitated bringing it into the "garden" for all the reasons you've
mentioned. Container planting--here we come. I have yellow iris and Iris Virginiana in the pond and too many cattails are in the retention pond in the built up area.

Chris

My containerized E. hyemale has performed all summer to colonize this large pot. First, a pic from earlier this summer - and then a pic from this morning. I imagine this plant will grow for another month and a half at least. It sent up many spore-cones, but they were small and delicate and seemed to fall off with the slightest suggestion of wind, water, or touch.

That's all for now. Not bad, eh?

Josh

Woodwardia fimbriata is not at all likely to establish in Zone 5, particularly in the eastern part of it.

Josh

Josh

Josh