Gardening Basics - Monthly Tips

Monthly Tips

May - Plant of the Month

Out with the hebes, in with the...

I used to grow hebes - and coprosmas, and gardenias, and New Zealand flax, and sundry other marginally hardy shrubs that have all been taken by that duo of PNW plant death - early frost and soggy soils. Of course the gods of plant death don't always kill plants outright, instead they leave them barely alive, tattered and decimated, so you're not sure if you should try to baby them back to health or ruthlessly yank them out.

Hebe 'Coed' - among the dearly departed

Well no more! It's a new house and a new credo - only tough survivors here (and that cool echeveria I bought the other day).

The problem is that after this last winter, some of the things that I thought were tough survivors are looking a bit wimpy. Ceanothus and raphiolepis are a little iffy around here I grant you so some of them dying off isn't that surprising, but Nandina domestica (heavenly bamboo), really? If you can't rely on your heavenly bamboo, what can you rely on for evergreen structure?

Why the shrubs you see in old neglected yards of course. They are your real survivors. Yep, I'm talking rhodies*, camellias*, pieris, conifers, heaths and heathers. Sigh. So mundane, so ordinary, but like the Energizer bunny, they keep on going, winter after winter. The upside is there are lots of new cultivars of these plants out there; the downside, most need summer water to look their best and flower well.

So what evergreens am I going to be planting? Hebe albicans 'Red Edge' has come through great the last two winters, it stays on my list. The Sarcococcas are glossy and healthy and can take dense shade - never letting those go. Pieris, probably. Camellia, particularly sasanquas, yes. Rhodies, maybe. I'll still plant Ceanothus, many made it through okay and they are so glorious in bloom I'd miss them terribly if they all went. Heaths (Erica sp) and heathers (Calluna), yep. I'm thinking of planting nothing but heaths and heathers with a variety of foliage and flower colors to create an ever-changing, weed smothering tapestry and calling it the yard.

Also, Osmanthus, Garrya elliptica, Viburnum davidii and Lonicera nitida. Surely, surely two bad winters and a cold, wet spring will appease the gods of plant death. I'd hate to send the heavenly bamboo to the compost heap along with the hebes, gardenias, New Zealand flax, coprosmas, prostrantheras ...

*Rhodies have pages and pages of disease and insect issues. Go to the Great Plant Picks site and pick ones that will work best for you. Already have root weevils in the yard? Make sure you get a weevil resistant variety. Heavy wet soils? Look for ones less prone to root rots, etc. Have heard rumors of some camellias not faring well this past winter although I haven't seen it.

May - Tip of the Month

Soil types

Loam soils. They are the holy grail of gardening and farming, but what exactly is a loam and, more importantly, how do you get one? Well, if you live in Puget Sound, you don't. I'm sure there are some around but if you don't already have a loam soil you can't make one - you'll just have to move if you really want one.

Photo from NRCS

A loam soil is one of many soil textures. (See triangle.) The percentage of sand, silt and clay sized pieces give a soil its texture. Sand sized grains are between 2.0 and 0.5 mm in diameter, silt 0.5 and 0.002 and clay <0.002. A loam has about equal amounts of sand and silt and between about 8 and 30% clay. The percentage of these grain sizes in your soil has a huge impact on how well water moves into your soil, how quickly it dries out and how well (or poorly) it holds onto nutrients.

There's not room to explain why here. I started to try and quickly stopped. In general you can assume the following:

Sandy soils - can absorb a lot of water fairly quickly without it running off; dry out quickly so you need to water more often; water doesn't spread out within the soil so you need to put soaker hoses or drip irrigation heads close together; it doesn't hold onto nutrients well and is more likely to lead to pollution of ground water because water (and the dissolved nutrients in it) pass thru it quickly
Silty soils - tend to erode readily; have fairly good water holding capacities and reasonable water draining capacities and nutrient holding abilities
Clay soils - are difficult to re-wet if they dry out and it must be done very slowly; once wet they stay wet for a long time; root rots due to water-logging are much more common than in other soils; nutrient holding capacity is high.

And the loam? The best of all worlds - good drainage AND good water holding capacity AND excellent nutrient holding ability.

How do you know if you have one? There are two methods you can use to find this out at home. Go to www.puyallup.wsu.edu/soilmgmt/Videos/Video_SoilTexture.htm for the "feel" method and to www.finegardening.com/how-to/articles/hows-your-soil-texture.aspx for the "jar" method.

So you don't have a loam, can you make one? No. (Don't believe me? Check the blog, It'll go into it in more detail.) Fortunately, you can improve your soil's water holding, water draining and nutrient holding abilities and in other ways, but that's the story for next month.