I don't know, but my kinnikinnick has been awfully slow at covering the space. After a couple of years I planted more between the original ones.

If you don't get an answer here, try the ground cover forum.

12"o.c. is a bit close - I'd stretch that out to 18-24"o.c. Coverage won't be quite as rapid as with a closer spacing but you will still achieve complete coverage of the area with less plants. Groundcovers are typically planted at some distance less than their ultimate potential spread so that they knit together tightly and provide a continuous mat. IMO, the Taiwan creeper (Rubus calcynoides) will provide much better weed suppression than the kinnikinnick and at a faster rate.

My own experience using kinnikinnick as a groundcover was disappointing because I had to keep weeding and weeding it. It just wasn't dense enough to keep the weeds from coming through it.

What about Lysimachia nummularia 'Aurea'? Or is it horribly invasive in the PNW? My experience with it here in Eastern 7b is that it is a FAST, mostly evergreen, groundcover. Now, I didn't plant it on purpose...it escaped from a pot...and I had to resort to Round-Up to get rid of it...but it covered quickly. It's pretty, too.

I'm unfamiliar with kinnikinnik...but the picture on GIS gives it a similar look to lysimachia.

melanie

Bearberry is slow at first but makes a nice mat later if the site is right for it. Like other manzanitas it wants a sandy soil and turns black if the foliage isn't dried quickly by the sun each day. The Rubus, represented in local commerce nowadays predominantly by the UBC introduction, is handsome and distinctive but has lots of nasty little thorns that can make weeding a planting of it unpleasant. I found this out because a friend once had a creeping jenny lawn with a planting of trees and shrubs, underplanted with creeping Taiwan raspberry groundcover arranged around the lawn in a sort of horseshoe shape. For awhile the lawn seemed to work but, inevitably it became weedy - this may have reflected how much time was being put into it, when I first saw it it's possible he was keeping it weeded and over time, lost interest (his wife eventually divorced him, showing how things there were going generally).

Sticking fingers into the raspberry to work out weeds was painful. Don't remember if it was coming through gloves or not, but probably does penetrate some styles - as do many other armed plants.

Mat-like plants all have the disadvantage of being too short to exclude weeds. And some kinds, including the Rubus tend to tear up with the weeds being taken out, have to be pushed back into position each time. To get serious coverage you really need to plant something at least 18" thick. Even then alder trees, blackberries and the like will occasionally insinuate themselves and have to be jerked out before they get too big.

I can't say that I have had any problems weeding around the Rubus calycinoides, which in my opinion is much better at suppressing weeds than Arctostaphylos uva ursi. The prickles on the Rubus are not a problem with ordinary gloves, and if the area is well mulched, it will easily root in as it spreads. If you want to go with a faster growing Manzanita, I would suggest A. 'Emerald Carpet'/A. edmundsii 'Carmel Sur' or A. uva ursi 'Radiant'. You might want to get local feed back to see if these are equally well adapted to your local conditions, but they are all very fast growers here in coastal northern California conditions.

I looked at the Golden Creeping Jenny but everything said to not let the soil dry out between waterings. The septic field's drainage will assure drying out. The Radiant kinnikinnik looks very nice but has the same slow growing problem as the Pt. Reyes. The most important requirement for planting on the drain field is the plant having shallow and non-aggressive roots. I'd like the planting to be fast spreading and able to smother weeds. I wish there was a sun loving Vinca minor. At this point I'm starting to consider growing grass over it. Tom

You do know that turf grasses are the most widely used form of groundcover :-)?? Certainly an appropriate plant choice over a septic field, as is pretty much any other commonly grown groundcover.

My experience with the Rubus is much the same as bahia's - relatively fast growing, tolerant of a range of conditions and much better at weed suppression than many others. And the thorns are small enough to be a non-issue, IMO.

I guess the ultimate determining factor in addition to the considerations aready mentioned is how it looks/functions in the location you have slated for it and how well it blends with the other, adjacent plantings. Other than a couple of mounded or bermed septic fields I've encountered, most seem to be flat expanses that might be best served by just a simple lawn.

gardengal, the field is flat. It will bordered on one side by the driveway and a veggie garden on the other. I wanted to look at planting beyond the usual lawn but the lawn is probably the best planting for the spot. Thanks! Tom

If you're totally into gardening you could plant a grassy mead, but that would be quite a project!

I'm only chiming in here because I have knickinick as a filler in my garden, I love it, because I love the look of it. The first year I planted it I was sure I had made a mistake. One part of one plant died, and the rest just sat there and I thought it would die soon too. Now, the second year, it has REALLY taken off! It's spreading like crazy. But it will never be a dense, dense groundcover. For my garden, that is a plus. However, all it takes for me to keep that bed looking good is a little weeding once and a while. I think knickinick is good mixed with other things, like evergreens. I have mine mixed with a low growing blueberry bush and dwarf hemlock.