Gardening Basics - Monthly Tips

Monthly Tips

April - Plant of the Month

Euphorbias - Spurges

Euphorbias - How I have grown to love them. Most have chartreuse "flowers" that last for ages. What you see and think of as the flowers are actually something much tougher than flower petals called bracts. You have to get down and peer into what appears to be the flower to see the actual flower. One can avoid this naming problem by grouping all the bracts and flowers on a stem together and calling them an inflorescence. Whatever you want to call it, the showy part of the euphorbia puts on a fabulous show for us here in the Puget Sound area.

A fabulous show you may ask? The "flowers" are only a yellowy-green - chartreuse sounds better - but how they glow on our gray days. In addition to long-lasting chartreuse inflorescences, many euphorbias have colorful new growth, often in shades of burgundy or red.

Not all euphorbias are dream plants. Some are nasty weeds that sow themselves about without restraint or spread by underground runners. Some, such as Euphorbia amygdaloides var. robbiae (aka Mrs. Robb's Bonnet), spread by seed AND runners (oh joy).

My current favorites among the large euphorbia clan are the Euphorbia martinii cultivars such as 'Red Martin' (almost in bloom in photo at right), 'Rudolph' and 'Blackbird'. They all have new growth that starts out some shade of burgundy. They are all evergreen and reach a height of 1.5-2' with a similar width. E. martinii hybrids like moist soil but certainly have done well for me with average watering. They also like part-shade.

One other euphorbia I particularly like blooms a little later and has orange bracts. It is Euphorbia griffithii 'Fireglow'. It reaches about 3'x 3' and is deciduous. (It dies back to the ground in the fall.) It has long dark green leaves with a hint of red and a pale midrib. An altogether good-looking plant, and for some of us, a welcome jolt of bright color in a sea of springtime pastels. For others, well, no orange, no way. E. griffithii and it's cultivars like sun, and well-drained soils.

You can cut your euphorbias back to new basal growth when the color starts to fade for a more compact plant. On some, I like the look the bracts give if left on the plant. If cut back promptly, you can keep the self-sowers from being able to do their thing.

NOTE: The stems and roots of euphorbias have a caustic sap that can cause skin irritation. Wear gloves when working with them and wash off sap promptly if you get any on you.

April - the days are getting longer, some are even warm and sunny, things are in bloom and the urge to go out and acquire some new plants is strong. Realistically, in the Pacific Northwest, fall is the best time to plant, but now is good as well. There are probably still a couple of months of wet weather in which the plants can get settled, and many plants are available at the nurseries - quite a few of which may NOT be available come fall. Plus, the urge is on us now and by fall, many of us are tired of gardening.

So, how do you recognize a good plant when you go to the nursery? Well, to begin with, does it look healthy? Are the leaves perky or droopy? Are the leaves a nice green or do they look sort of yellow? (Beware, some leaves are meant to be yellow.) Are the edges of the leaves brown or crispy? (not a good sign) Are there any insects? Make sure to check underneath the leaves. You may not see insects but there may be signs of insects. Obvious bites out of leaves would definitely qualify as a sign. Webbing on the underside of the leaves may indicate the presence of mites. Is there evidence of disease such as powdery mildew?

One common problem that happens to plants in nurseries is that they get dried out. Another is that the plants grow but don't get moved on to larger pots so they become rootbound. You should check to see if the plant is rootbound. (See photo.) Roots coming out the holes in the bottom of the pot are not a good sign. If you slide the plant out of the pot, you should see a tracery of white orrootbound plant pale colored roots (on most plants). If the roots are brown or black and mushy, don't buy the plant. If there are roots circling around the pot or there seems to be nothing but roots, the plant is rootbound. This is a very common phenomenon and you should try to avoid buying plants in this condition. Sometimes you do, and next month I'll talk about planting and how you deal with rootbound plants.

Lastly, look for a plant that is well-branched and stocky. If the plant is in bloom, look for one that is just beginning to bloom rather than one in full flower - you want the bulk of the blooming to happen at your house, not the nursery.

If, after all this, you find a plant that pleases you, buy it and take it home. Next month we'll talk about how to plant it properly.