Like many of you, I have 6 foot cedar privacy fence between my back yard and my neighbor’s yards. I’ve been trying different ways to break up or hide the visual effect of those long flat expanses of fence. One approach I’m trying is to put tall ornamental grasses in front of the fence.

The one on the left is Hardy Pampas grass ( Erianthus Ravennae). The one on the right is Giant Chinese Silvergrass ( Miscanthus Giganteus, or Miscanthus Floridulus) This pic was taken in August. This is the 3rd summer’s growth of both of these. I planted about 6 very small single stem starts of the pampus grass more or less in a row about 6 or 8 feet long, and I put in 4 similarly small single stem starts of the Giant grass also in a row spread out over about 5 or 6 feet. This is the first year they are big enough to have a considerable visual impact in relation to the fence.

Although similar in size, the two have surprising difference in appearance throughout the year. I cut them both down to 1 foot around first of May. Then....

The Pampas grass shoots up pretty quick and by mid June is bushy and about waist or even chest high. Then it just stays like that, and fills out with more of those long green leaves until mid to late August. At that point these big long stems come shooting quickly up a good 8 to 10 feet high, and the plumes open and become gradually more fluffy over the following weeks till first hard freeze, when everything turns dry yellow and brown. That October snow storm brought most of them down this year. You can see they’re leaning a bit in this pic, so the snow just pulled em down, and I’ve now cut off the down ones, (the kids love to play with them) but the rest I think will look nice through the winter. I think as it fills out and has more old dead stems to hold everything upright at the base, the stems will not tip over as easily in future years.

The Giant Chinese Silvergrass comes up and shoots up about the same time around last frost, but it just keeps right on going till it’s about 6 feet by mid June. Then for the next 2 months it mostly fills out at the level between 4 and 7 feet, and gradually gets only moderately taller. By middle of the summer the lower portion has the appearance you see here, just stems with a few dry yellowed leaves. The top portion seems more like field corn from a distance. It doesn’t really change in appearance much from Mid June till first hard freeze. Shortly before hard freeze about half of these put out modest sized plumes, but smaller than the pampas and nearly still tucked into the upper leaves. I can see that perhaps by next year or the year after that, the Giant grass will simply be a solid 7 foot wall, tan on the bottom half, and green in the upper half, from mid June till hard freeze, and then all brown and yellow through the winter, till it’s chopped down again the following spring.

The pampas grass must store energy in roots throughout the summer and then suddenly expends the stored energy in August to make those big stems and plumes. The giant grass must store energy all summer in the roots, and it lays latent there through the winter like a bulb or tuber, and then expends the energy suddenly at the beginning of summer to send out tall stems, atop which will be the greenery to develop energy for the next cycle. Viewed through the evolutionary lens, the Giant must be more concerned about getting out ahead of and above its crowded neighbors to grab sunlight. The Pampas must be less concerned about crowding and more concerned about getting its seed plumes high enough to catch the wind, or catch the attention of birds. I wonder if the giant propagates mainly by root spreading, and the pampas mainly by seed? Can anyone comment?

So if my objective is to hide the 6 foot fence completely from view, the Giant grass is clearly a better choice. However, I think if I had a long stretch of this stuff along my fence, my back yard would start to look like it has accidentally butted up against a sugar cane field. It would look more natural, but not really much more visually appealing than the 6 foot wooden fence. The pampas grass is much more visually appealing and changing throughout the season. I like the way the tall stems and plumes blow around and add motion and color in the fall and even winter. Over all, I like them much better.

I’ve just realized that if I use a little imagination, and in my minds eye, if I move the pampas grass in front of the giant grass, then I have a really terrific screen. The fence would be quickly and completely blocked in early summer by the tall giant grass, and the height of the leafy green part of the pampas grass is just about right to hide the brown stemy part of the giant grass, and at the end of summer the tall plumes will have a leafy green background. The Giant grass seems to need about 2 feet of width, and the pampas grass looks more like it wants about 3 to 5 feet, depending on whether I’m counting all the space at the front where the leaves spray out. So all together I’ll need about 6 feet width from fence to lawn.

Now I’ve got a plan. Next spring, I’ll try digging out the back half of some of the pampas clumps and move them over in front of the Giant. And vice versa, I’ll chop out the front of some of the giant grass clumps and move them over behind the pampas grass. Then I’ll have to wait 2 more years to see how it all works out. Eventually I might need some kind of root barrier between the two, but that’s got to be several years out. I’ll cross that bridge when I get to it.

I’ve also been trying clematis, trumpet vine, and virginia creeper to screen or break up the fence, but I’ll save that for another post.

Have any of you had any luck with things to change the appearance of fences, do screens, or do you have any nice examples of use of these large ornamental grasses?

Bruce

We've been growing pampas grass the last few years. Last summer wasn't remarkable. It may be b/c we didn't fertilize or water enough or perhaps not enough sunshine. Do you cut the dead back to the ground in the spring b4 the new chutes start? We had been and maybe that's why they're not growing to their original heights. I hate to use fertilizer anyway, so let me know. The grasses spread by seed b/c either the wind or birds planted them into our bog area. Over the years I've not seen them send out runners.

Also we use virginia creeper. Our neighbor had planted trumpet vine on their fence, but we get most of the blossoms and seed pods. I understand that they will spread. Virginia creeper doesn't need support, but TV does. Thanks! Paul

I think I dumped about 2 bags of Wal-Mart steer manure on the string of ornamental grasses seen in the pic above, around May 1 last year, right after I chopped them off. I cut off everything above about 6 inches. This Spring I’m going to try leaving it a little longer, maybe 12 or 14 inches tall. My thought is this might give it more strength and help it stay more upright when the snow hits.

So far I haven’t seen any new ornamental grasses come up anywhere from seed. I don’t get the feeling they start from seed all that easily. The Giant grass sends out runners about 6 or 8 inches from present grass clump. No further than that. On the Hardy pampas the new stems are in very tight to the old. I’d say it spreads only an inch or maybe 2 inches per year.

I read somewhere that these tall ornamental grass varieties are very responsive to Nitrogen fertilizer, so you might want to consider putting a little manure or something on yours. If not that, then I imagine a little cheapy lawn fertilizer (without the insecticide and weed killer) would also make yours very happy.

The Giant silver grass is being used in Germany for the stuff to put into the fermentation vats to make alcohol motor vehicle fuel. Apparently it grows more fermentable mass per acre than any other crop. In pictures of it growing there, it seems to be about 14 feet tall.

Bruce