Given proper support and spacing, brambles will get enough airflow to avoid mildew, and allow better pest management (like picking off Japanese Beetles). You can solve these problems by building a bramble trellis. Here’s my history with raspberries, what I have built wrong in the past, and what I am building now.
When I first purchased raspberry plants several years ago (two No-ID plants from a yard sale) I had no idea of how they would grow, nor did I have Internet service back then to do any research. So I just plunked them in the dirt about 3 feet apart and 3 feet away from a hand-tied bamboo fence I was building. The following spring each plant had 2-5 new ‘canes’ coming from the roots.
By mid-summer those canes became 6 foot tall thorny beasties, flopping everywhere. I figured they needed some restraint, so I extended the bamboo fencing to the sides of the raspberries and also higher, making a “U” shaped area. The canes kept growing so I added a few bamboo poles across the top. I tied the raspberry canes to the top poles, and it wasn’t too bad… until the fruit got heavy on the canes and pulled the poles down. Over the next 3 years, more and more new canes grew until I had a thicket 4’ x 12’. It was so thick in there I could seldom find the old dried-out canes to cut them down, and picking berries every morning and evening ahead of the birds became a daily battle with the thorns.
Then I discovered the Internet and Dave’s Garden…. There was little or no information on fruits and nuts at that time on DG as the site was less than a year old. However, folks here sent me to some search engines where I found several trellis ideas to control brambles. Now, if you have only a few raspberries, you can get away with a pole or fence post for each clump, and just tie the canes to it. However, if you have very many raspberries and blackberries (or marionberries, juneberries, loganberries, lingonberries, thimbleberries, wineberries, boysenberries, etc.) then a trellis is very helpful, and makes sense to actually control runners and facilitate picking the berries.
The first trellis I built was out of pressure-treated 4x4 posts in the ground, and a 2x4 treated crossbar with a single wire up the center. I’m sorry I don’t still have those pictures from several years ago so I could show you what didn’t work very well for me. One factor I didn’t like about my first trellis was using a toxic material around something I would eventually eat. It is bad enough that I purchase food that could be contaminated without deliberately adding it to the food I grow.
I’m building another (and better) parallel trellis here at my new place. This trellis will afford sturdy support during the various stages of bramble growth, from new shoots through fruiting. A benefit to trellising my earlier raspberries was increased yields, which I expect here as well. I believe it was because the trellised brambles got much better air circulation and sun exposure; I had no signs of mildew, and few pests. The goal of this new trellis construction is to provide lower support for newer canes as well as support higher up for the current years’ fruiting canes. Also, to provide a place to direct emerging growth of new canes, or even a place to transplant wayward canes that escape into the yard.
Brambles are either primocane (they produce fruit on the new canes) or floricane (they produce fruit on last year’s canes) and I have some of each that came from various plant swaps and mail-order. My trellis is designed to accommodate both types since I’m not sure which is which at this time. (With primocanes, you can mow down the canes each fall.)
The trellis I’m building here is for raspberries, which are not as heavy on the canes as some bramble fruits. Therefore I will space my end poles anywhere from 15 feet to 25 feet apart. However, other types of brambles may fruit more heavily, so you will want to space your posts accordingly and/or alter the number and height of the cross members. My cross members will be attached at 16” off the ground, and 36” off the ground, screwed onto the upright posts so I can move them up or down, or add additional cross pieces as I gain experience with these brambles I have.
I have learned that I am not strong enough to tighten the actual support wires between the posts without tensioning clamps of some kind for the wires, so I chose to span 20-25 feet between poles and use turnbuckles to tighten the wires. The more expensive tensioning clamps would be nice but I can get by with just using turnbuckles, one per wire.
The end poles look like old-fashioned clothesline poles only shorter, with a second set of cross pieces even closer to the ground. For raspberries, my first cross piece and wire will be about 14” off the ground and the second will be about 36” off the ground. If I had blackberries, which generally have longer canes, I would place both support wires higher, maybe 4”-6” higher for the lower wire, and perhaps a foot higher for the top wire.
Each of these new posts will have 2 cross members, fastened at the height I want my support wires. Since I want the bottom portion of the canes closer together than the tops of the canes, my cross members will be 2 different lengths. The lower cross member will be about 2 feet long and the top member about 3 feet long. I will screw them to the posts I placed in the ground, allowing for later adjustment(s) in height.
Esthetically, I would prefer to use galvanized bolts rather than screws but since I am unsure of what brambles I may add to this ‘garden’ later on, I chose screws for versatility. Galvanized carriage bolts are less expensive than galvanized bolts with nuts and a lock washer, but with a winter of freeze-thaw cycles, they do get loose and eventually the inside lug (under the cap end) will no longer bite into the wood to hold them tight.
To begin, I marked the distance and dug the holes for the posts. Our freeze depth here is about 12” so my holes are 16” deep. I used 2 pieces of Western Red Cedar 2x4 screwed together for the posts. (4x4’s would have been nicer but no lumberyard locally carried them.) The tops are angled so rain doesn’t sit on the posts, eventually rotting them. I plumbed the posts, backfilled and tamped the soil in place.
|Level the Cross-Pieces||Plumb the Posts||Close-up of Level Vial|
Normally I would make a ‘soil cement’ mixture to set my posts but I may want to move these posts eventually. The soil-cement mix I have used in the past is half dirt and half Portland cement mixed together, dry. Add it to the post-holes, plumb the posts, and let rain or a trickle of water harden the mix. Since I didn’t use a soil cement, I have installed guy wires on each post (and might have done that anyway). They are anchored to the ground by a 24" steel bar driven at an angle away from the posts, about four feet from the posts and secured with a wire and turnbuckle.
Next, I added the cross members at the heights I wanted, leveling each one as I went along. Then I drilled a ¼” hole for my galvanized eye bolts, and fastened the eye bolts through the cedar using a flat washer (so they don’t cut into the soft cedar) and a lock washer before tightening the nuts. This is necessary as the lumber will expand and contract during the winter freeze-thaw cycles and loosen the nuts without lock washers.
I used green vinyl-covered wire clothesline for my support wires, with a wire clamp at each loop of wire. One end of each wire has a turnbuckle with an open hook at the far end. (A turnbuckle is a small metal device with a hook or eye screwed into each end; one has a right-hand thread and the other has a left-hand thread. When the center piece is turned, both ends screw into the center, tightening whatever wire is attached to them.) This kind of turnbuckle allows me to either tighten the wire, or to take it down if I want to mow or do spring/fall clean-up inside the wires.
| Eye Bolt
|| Flat Washer and Lock Washer
Instead of the wire clamps I used, there is a permanent fastener available (usually called a splicing sleeve) where you insert both pieces of wire into a 2-barreled short tube, and crimp shut. However, in my experience with this particular clothesline wire I’m using, the wire stretches even though the packaging says otherwise. Sometimes it can stretch by an amount greater than my turnbuckles can tighten. With the wire clamps I’m using I can loosened the nuts so the wire can be tightened by hand as the clothesline stretches, re-tighten the nuts, and then tighten the wire fully with the turnbuckle.
My neighbor who just built a fantastic grapevine trellis gave me some of the high-tension wire he used. With that wire, there is no stretching. However the wire was so strong that I could not even bend it nor cut it so I opted for the clothesline wire in the end. (In a rural area like mine, selection is generally scant at most hardware stores.)
You may notice in the photos that the top cross member is not centered on the posts. I deliberately offset them by several inches. There will be a second berry trellis row parallel to this first row, and those top cross members will be offset the same amount but in the other direction. This will allow a little more room for me to walk between the rows without taking up more ground-level space for the additional row.
Of course, it is not really necessary to use all the materials I did. You could easily use any fence posts, and any wire. You could just wind the wire around the cross members, too… no hardware required. Since my trellis is in my front yard, I wanted something that looked pretty even in winter when all growth is dormant and leafless.
|Raspberry Canes To Be Transplanted into Trellis||Red Raspberries!||Berries on an old Single Wire Support|
All that remains for me to do now is to transplant my raspberry bushes when the moon is in the right sign. As the canes grow, they will hang over the top wires but right now, they are too small. I am leaving the 3 black currant bushes already planted at one end of this trellis for the time being, as I hope next year to build a net cover over the whole shebang to keep the birds out. The currants are new this year too, but even so they produced about 2 cups of currants… which were there one day and gone with the birds the next.
If you enjoy having cane fruits in your yard, build a simple trellis to help keep your berries healthy and tidy.
Photo Credits: All photos are by the author except the red raspberries © Joe Cicak, #4602828 iStockPhoto.com, used by permission.
Spiced Raspberry Jelly
Adapted from Gourmet Magazine - June 1967
4 cups raspberries
1/2 teaspoon cinnamon
1/4 teaspoon nutmeg
1/4 teaspoon mace
1/8 teaspoon cloves
In a saucepan mix together all ingredients EXCEPT sugar.
Cook the berries over low heat, stirring and crushing them with a spoon, until they are soft. Pour the mixture through a jelly bag, without squeezing the bag, and measure it. For each cup of juice stir in one cup of sugar and cook the syrup over low heat until a little jells when dropped on a cold plate. Pour the jelly into hot sterilized glasses and seal. Process for 5 minutes in a boiling water bath.
May be served as an accompaniment to roast meats and poultry. ENJOY!