Low groundcover for sunny slope

Hello everybody, this is my first post here and I need your help choosing a groundcover for a troublesome spot along my driveway in zone 7b (east of Woodinville).
As you can see on the picture I have a 4x60 foot long strip of soil on both sides of my rather steep driveway. It has typical PNW soil (clay, rocks), but I've been amending it with good amounts of compost for last few seasons. It is very dry and hot during the summer, I would say at least 10 hours of full sun and close proximity of asphalt driveway that radiates the heat baking everything around. As soon as I started amending the soil I started having huge problems with weeds coming from nearby fields. I need a suggestion for a short (no more than a foot, but preferably shorter than that), drought and heat tolerant groundcover that would effectively smother the weeds, stop or at least limit soil erosion and help retain some moisture for larger shrubs growing there right now. Those on the picture I removed as they struggled badly throughout the summer.
Thanks so much for your help.

Hi enith. Welcome to PNW forum. You do have a tough situation. Have you thought about using Preen for pre-emergent weed killing. That would take care of most incoming seeds. I don't know of any groundcover that will truly keep weeds from growing. Does the strip get water? Watering only the shrubs would help. Someone else will probably jump-in and have more suggestions once they discover this thread. I will think on it somemore also.

Hello enith,
I've used periwinkle, also called creeping myrtle, up in Ferndale and have had much success. It didn't keep the weeds out so I clipped it back, weeded then put a heavy layer of bark down around it. In one season it filled in fast, completely covering the bark and only had a few blades of grass come up next to the plantings. It will creep into the lawn a bit but the mower takes care of that pretty well although it still puts runners deep in the sod. The bark will help hold moisture and the periwinkle will hold the bark from blowing on the driveway after it is established. I planted about 12" apart and shoots can get a foot tall but they usually bend over and stay around 3 to 4 inches.

Here's a link to it: http://davesgarden.com/guides/articles/view/1742/

Tom

Thank you for suggestions.
Willowwind2, about a month or so ago I used pre-emergent organic herbicide and now I have less problem with weeds sprouting, but also it haven't been raining in last 80 days, so I cannot definitely tell which helped with weeds, lack of rain or herbicide. I do water only the shrubs to minimize weed problem.
Spitzkopf, I have abundant vinca growing in moist shade in my backyard and I don't think it will do good without supplemental water and in scorching sun. I need an actual heat and drought loving plant that will also survive a typical PNW winter. I will however take some rooted cuttings of my vinca and give it a try in my problematic spot. If it takes off, I will use it on the entire strip. If not, I'll keep looking.
Thanks again!

You could try a few ceanothus (california lilac) to see if they would work. They have an upright one and a spreader. Beautiful purple flowers in May. Bees love it and it is evergreen. Probably spelled it wrong. With anything you put in it will probably need water for a few years until it gets established.
Lavenders might work. They spread out after a few years.

How about a mixture of low growing sedums? I've found them to be fairly bullet-proof.

I have tried lavender in this spot a couple of years ago, but it was my first attempt in gardening and it failed: I bought lavender not hardy enough, didn't mulch it, that first winter was very cold and all 20 little shrubs died. This year I already got hardy lavender ('Grosso') and will give it a try.
Low sedums sound great! The only thing I fear is the winter wetness as it might cause rotting. I will give it a try though, as sedums are so easy to grow and there are so many different kinds!
Thanks everyone for your time!

Creeping thyme or Mother of Thyme? Someone gave me a few rooted plants, and I thoguht I had killed them, so I put the4m near some sedum that was coming along OK.

A month or two later it had smoothered the sedum, shouldered all weeds aside, is still spreading and is in heavy bloom. But I have been watering it (when I remeber) and gave it some half-amended soil.

>> hot during the summer

I wouldn't call my few weeks that reached 80 "hot". But my tiny test was in the sunniest part of my yard, a tiny raised bed with asphalt on twoi sides. Maybe "warm".

This message was edited Oct 10, 2012 6:54 PM

Two low-growing groundcovers for you to consider: Arctostaphylos uva-ursi (a PNW native, the common name is Kinnikinnick or bearberry), and Lonicera crassifolia (it's a type of honeysuckle, but I've never seen it sold other than under its Latin name). Both are low growing, dark green, glossy vining ground covers that do fine (once established) with dry conditions. The Kinnikinnick actually does best if it dries out between waterings. The Lonicera will tolerate more water than the Kinnikinnick, so if you plan to water your lawn or shrubs regularly, it might be a better choice. Both plants have small pink or creamy pink flowers in the spring. The Kinnikinnick has edible (although not that tasty) berries in the fall. One of the many types of cotoneaster also might work for you. All are less invasive than vinca and require less water in my experience.

I agree with the cotoneaster. I have it out on a bank by the street and it never gets supplemental water. I have it with juniper and some iris and ivy. Not english. There is also a daffodil that comes up every year right in the middle of a juniper. I will take a picture.

Here are the pictures of the jupiter, cotoneaster, and ivy. With iris.

Taken from the street. The iris just come up and bloom every year.
Cotoneaster looks like it is laying on it's side.
With ivy
More with ivy.
From the front porch.
Be sure to enlarge them.

Rick, I might try thyme. Previous owners had a few shrubs of lemon thyme planted in that spot, but I removed them as they became very leggy and woody. I would maybe try wooly thyme instead, as it might enjoy dry and warm soils on the slope and is super low growing.
Fernfarmer, as much as I would enjoy having a native plant in this spot I already have kinnickinnick in my yard, but it seems to suffer from some kind of disease (blackened leaves). I'm reluctant to put in more of it at least until I figure out what's bothering these I already have. I have never heard of Lonicera type you mentioned, but I'll look for it in nearby garden centers. Cotoneaster is, in my humble opinion, too vigorous for a spot that is only four feet wide and borders neighbor's lawn and my driveway. I would be probably constantly chopping it to keep it at bay.
Willow, I love the pictures, those are some nice plant combinations. Is this cotoneaster always that red or it's already changing leaf color for fall? I also already have a low growing Juniper 'Daub's Frost' that maybe will make a nice carpet and cover the soil. This fall I will add some spring blooming bulbs until I figure which will be OK in this place. I was hoping for some miniature daffodils mixed with more sun and drought tolerant cyclamens.
I really appreciate your time and suggestions! You gave me great ideas, now it's time to decide and hunt for plants :-)
Have a great Sunday!

It does have it's fall color. Having no water does slow down or stop its growth. This has been here for fifteen years or so and pruned very little if at all. Didn't realize that was your neighbors lawn. Let us know how you finally finish the project.

I agree with RC_WA, I like the thyme route but over here in Spokane I prefer Woolly Thyme. It is silver in color, drought resistant, stems turn a slight purple in the fall, and absolutely love full sun. I planted three, two inch pots in the spring and they filled close to six feet in one year. Down side, very little fragrance, and they choked out some of my flowers. But they don't mind being cut back. They just laugh at the garden knife and take off again.

>> and they choked out some of my flowers

Thats probably a concern with my nerw thyme, also. If it can choke out SEDUM, it's pretty agressive!

I'm chiming in here late, but I would consider going with something that's native and drought-tolerant, and this would mean ditching the soil amendments. Drought-tolerant plants need to establish symbiotic relationships with the natural fungi and bacteria in the soil, and this does not happen when extra nutrients are available. (The fungi/bacteria detach from the roots and the plants soak up the nutrients. Unfortunately, the absence of protective fungi/bacteria on the roots leaves the plants wide-open to attack from pathogens, and they tend to have blight and leaf spot problems, eventually followed by death.)

If you're interested in going this route, I'd suggest planting some annuals in this spot for this year to soak up the extra nutrients in the soil. When they die in the winter, tear them out and bury this spot in about 3" of pine/fir bark mulch (oak and redwood mulch will also work). You are now probably ready to plant something that will last long-term with minimal water. Kinnikinnick, which has already been suggested would work well here. Some of the other lower-growing manzanitas, such as Carmel Sur (A. edmundsii), Franciscana (A. hookerii), "Wayside" A. hookeri, will probably work here next to your lawn, and can be sheared into a hedge. Some of the sagebrush species, such as Great Basin Sage, will probably work here as well if you don't over-water the lawn. I wouldn't recommend Ceanothus in this spot. They don't do well next to watered lawns (they will for a few years, and then they'll die), this spot is kind of a tight fit (which means heavy pruning... not good for Ceanothus), and being in Zone 7b may limit your choices.

Pacific wax myrtle (Myrica californica) will also work here as a hedge. They quickly grow to 15-20' but can be held to 6'-8' if you shear twice a year. After they're established, they should be OK with water every couple of weeks in the summer.

[Oops, didn't read your height requirement of 1'. Sorry.]

This message was edited Feb 20, 2013 10:58 AM

Hi Mulching man. Thanks for the info on amendments and natives. Good to know.

I like creeping thyme as a ground cover....cheap, drought tolerant, and comes in a few different colors. I have found the variegated ones not as agressive as the others. Another possible groundcover for a hot dry area is Germander: Teucrium...don't remember the other part of its name. Spreading, up to six inches tall or so, pink flowers. All it needs is a little shearing now and then, and it fills right back in. Where you put it, you would need to want it to stay, as it spreads outward by the roots and would not be easy to get rid of later...for good or ill depending on your perspective.

Hi enith; have you ever looked at High Country Gardens? They have a lot of heat and drought tolerant plants. I used to get their catalogs and they have pre-planned "inferno strip" gardens. You could probably get some ideas from their site: http://www.highcountrygardens.com/

Thank you, lynnala. I will definitely look at this site! Last fall I tucked some creeping phlox among taller plants and it seems they all survived winter and are starting to grow, expand and set some blooms! Yay! Will see how they take drought and proximity of asphalt driveway in summer months.

We have a slightly hilled area in our yard that we wanted to be 0 maintenance and evergreen and with a low groundcover.

We put Creeping Raspberry (I've also heard Creeping Strawberry), Rubus pentalobus, plus a low groundcover juniper on the totally sunny side. We had the nursery pick the juniper out and I can't remember the name. It would be a Juniperus horizontalis or prostrate or repens.

The groundcovers are all duking it out and are spreading. They get no water or fertilizer (after the first few months to get some roots established). The Rubus pentalobus has a crinkly leathery leaf and gets a reddish tint in winter. It's gorgeous. The juniper is spreading thickly and looks great. I think both might work for you, so they are worth checking out.
In case you haven't seen the Rubus, growin' has a picture of what the Rubus pentalobus looks like once its filled in and also a close-up: http://davesgarden.com/guides/pf/showimage/121432/ and http://davesgarden.com/guides/pf/showimage/208183/.