Creating Water-Wise Landscapes Creating Water-Wise Landscapes A few good things to know... ... A few good things to know by Jean Marsh GARDEN DESIGN consultation & design especially for the homeowner 951-736 - 8941 Parkway Design Creating Water‐Wise Landscapes # 1 Rule as it regards water‐wise landscape design: Get Rid of the Lawn! Or at least the part that doesn’t serve a good (useful‐practical) purpose. Turf grasses (lawns) are the highest water users in the landscape, hands down. Can we have grass and still be water wise? The answer is yes, but a lawn area must “earn its space”. Our customary use of turf grass needs to be thoughtfully re‐considered. As lovely as a green park‐like expanse can be, the fact remains: it is not sustainable. Water is NOT a renewable resource ‐ in the case of suburban demand – we just don’t have it to spare. We can no longer rely on lawn areas as the default‐go‐to landscape solution. This long‐established “solution” is now a big part of the problem. All design begins with some sort of criteria, a set of rules or limits. Form Follows Function is the fundamental principal in my design philosophy. It is always the first question I ask when determining the criteria for any project. When I say the turf grass must “earn its space” it is the result of this thinking. Criteria‐Objective: we need to apply less water to the landscape – turf grasses have a very high water demand – if and when grass is used it must do more than just lie there and look pretty... So take a moment ‐ consider the parkway and the fact that: 1. a lot of water is applied to the turf in these parkways to keep them green 2. a lot of water also runs down the street every morning in every neighborhood because irrigating a parkway efficiently with sprinklers is a challenge 3. what is it that we do on these 4 to 7 ft wide patches of grass... Play soccer? Have a picnic, take a nap? Nope. So re‐designing a parkway and getting rid of the grass makes good sense. Relative to sustaining turf, it takes about 75% less water to support a colorful low maintenance garden as described in this workshop. Re‐thinking the traditional use of grass in the landscape opens the door to new creative design alternatives that incorporate color, texture, fragrance, and habitat... It’s a good thing. A Few Things to Know Before You Start: • A no‐fee encroachment permit is required for this project. C all the Water Resources group at (951) 736‐2234 for the permit application. • Call before you dig... At least 2 days before, to locate underground utilities like electric. The Phone number: 1‐800‐227‐2600 or 1‐800‐422‐4133. Hours are Monday thru Friday 6am to 7pm. If you need more information Google: SCE dig alert on the web. • Fire Hydrants: If you have one, you must leave a 3 ft clearance area all the way around it – no plants of any kind, mulch only. Old school “zero” scape... • No structures are allowed in the parkway – only mailboxes and utilities. •Any pavers need to be pervious. Parkway Design City of Corona 2 Parkway Design Step One – Prepare the Site Getting Rid of the Turf Most parkways are growing full of whatever blows in from the neighbors. In addition, mow blow and go gardening practices spread Bermuda and crab grasses as mowers and weed‐whackers drop cuttings from one yard onto another. The only really effective way I know to eradicate these weedy grasses is to use an herbicide like Round‐up. Success is all about the prep; how well you begin anything is usually how well it will turn out. Simply digging up the grass will not do the trick. Bermuda grows from little roots called stolens and they will tenaciously hang on in the soil, being opportunistic, any bit of water will cause them to grow. You can spend a lot of time, effort and money on this task only to be discouraged when your new parkway is infested with weedy Bermuda and that low maintenance garden I promised you is just another item on your Saturday morning chores list... We are trying to avoid that! Round‐up is a non selective herbicide in liquid sprayable form that is applied to the foliage and taken in by the plant clear down through the root system. 41% concentrate Round‐up is what most contractors use. It seems to work better than the pre‐mixed solutions of the same, I know it should not make a difference, but it seems to. Mix according to directions. Apply Round‐up when the breeze is not moving. Keep in mind this is a non‐selective Herbicide and if it drifts in the wind it can kill any plant it gets on. Round‐up works best when a plant is vigorously growing, so please don’t turn the water off thinking you are killing your lawn, more than likely it is just going dormant and will spring back to life when water becomes available again, the crab grass and the Bermuda will anyway. So spray the turf, give it a few days to a week to die. Hot weather speeds up this process. Remove the dead sod with a square point shovel. I don’t recommend composting, unless your compost pile runs pretty ‘hot’ because of the weedy Bermuda stolens. After raking out the area, now free of sod, irrigate again for a few days, the objective being to get anything that is still in the soil to grow or germinate. If weeds and Bermuda show after a week or so, spray again. Clean the area again. Depending on how big the second crop of weeds was you may want to go through a third cycle, until the area when irrigated does not produce a crop of weeds, or least not very many. Soil Preparation This next step assumes that you have a clean‐as‐a‐whistle parkway with no grass. Now is a good time to add amendments, such as gypsum that can improve drainage of heavy clay soils or more top soil if necessary. Use a landscape rake to establish a rough grade. Old school “zero” scape... Parkway Design City of Corona 3 Parkway Design Step Two – Drip Irrigation Drip Irrigation Drip irrigation has come a long way. It works, and it is not difficult for a homeowner to install. Retro‐fitting an existing sprinkler system over to drip is very simple. The first step is to select a point of connection or P.O.C., this will be the location of one of the existing sprinklers, the best choice is one centrally located – see fig. 1. Then remove all of the sprinklers, and the sch 80 nipple, (see step 1) plugging the opening of the fitting with a threaded plug (step 2) as shown in fig.2. This happens at each sprinkler location except where you are going to make your point of connection P.O.C. Fig. 1 Fig. 2 Parkway Design City of Corona 4 Drip Irrigation Every drip system needs filtration and reduced pressure. These things can be added at the valve, and if it is a completely new system it should be, but for an existing system it is often easier to do it at one of the most central points of the lateral lines (where you have removed the sprinklers). P.O.C. Point of connection. This is what I am calling that one location where the drip system is going to hook up, you have removed the sprinkler and the short nipple, but this time instead of the ½ inch plug you will put together the drip assembly that provides filtration, pressure reduction and a way to connect the flexible drip tubing. See fig. 3. Are there other ways to do this? Yes, but this way really works well – my motto “build it like a Buick”. This is pretty bullet‐proof. The entire assembly lays on the surface of the ground. It is important to never bury a pressure regulator, they need to ‘breathe’. The tubing and assembly will be covered with mulch when everything is finally planted. Fig. 3 Parkway Design City of Corona 5 Drip Irrigation The final layout of the drip tubing will look something like this. Looping the system, although not necessary, is a good idea. The ½” poly drip tubing is installed on top of the ground. Once this is done the plants can be planted. Then the emitters are installed, located at the edge of the root ball of each plant, as shown in the diagram below. A small amount of ¼” tubing or “spaghetti” line can be used to reach from the main tubing to the plant, but do not exceed 12 inches. Too much of this small tubing creates a maintenance headache... Fig. 4 Parkway Design City of Corona 6 Parkway Design Step Three ‐ Planting Plant Selection A clear line of sight is essential for safety when considering plant materials for the parkway. Generally plants for a parkway should grow 18” or less. There are a few plants on the list that have flower stalks that exceed that 18” height, but it is assumed that this is not dense foliage and can be seen through. If, after a time, a plant grows beyond the recommended height, either prune it or remove it. Use common sense ‐ do not block the view for traffic safety. The plant selection in this handout is based upon a few things: 1.