Azalea chlorosis

Or, Why Are My Azalea Leaves Turning Yellow?

Most of the subjects of the Great Azalea Migration have settled in well. I pruned them directly after this year’s flowering to give them more shape. Waiting too long to prune risks cutting off next year’s flowers.

This one, however, is showing signs of displeasure.

chlorotic azaleas yellow leaes green veins

Notice how the leaves are more yellow than green, but the veins remain dark green? This is a sign of chlorosis, a condition in which the leaves don’t produce adequate chlorophyll. The source of the problem lies in the soil’s pH; if the pH is not appropriate for the plant, that is, if the pH is too low (acid) or too high (alkaline), the plant’s roots cannot take up the nutrients (in this case, iron) in the soil. The solution to such a problem, therefore, is not to dump fertilizer on the plant, but to test the soil’s pH to confirm the diagnosis and then adjust it accordingly.

Azalea Growing Conditions

Azaleas like acid soil, typically in the pH range of 4.5 to 6. My soil falls within this range naturally. But it is possible that when this shrub was transplanted, some lime got mixed into the compost by accident; or it might have happened when I planted some smaller perennials at its base. Azaleas also want a shady location, or one that receives some morning sun. The light exposure is not the problem here.

This condition is interesting to me, because as you can see the older foliage is perfectly green. I would have thought the problem would be more evenly distributed on the plant.

So I will try to get a soil test for this patch of ground in the coming week or so. And if you are very good, I will show you the results and the remedy.


The way of all projects?

I am keen to finish the rain garden project. I don’t have very much left to do; perhaps 25 square feet. But, as always seems to happen, a few other responsibilities have preempted that work.

I am having a large tree removed from my garden this week. Continue reading

Last-minute chores

Wednesday’s weather was gorgeous. After sitting and sketching for my prospective rain garden, I did a few other chores I’ve been meaning to attend to:

variegated solomon's seal

I dug up and moved the variegated Solomon’s seal, Polygonatum odoratum ‘Variegatum’. This is one terrific plant; absolutely resilient in my acid clay soil and deep shade. It had been located close to the azaleas I’m moving, but since that zone of the garden is being totally revised, I chose to move the Solomon’s seal to the under-construction white garden. Imagine the thrill I felt when I discovered the plant I bought in a 4-inch pot two years ago was now about 24 inches wide. It divided rather neatly into about eight clumps, which I planted near the Korean spice viburnum (Viburnum carlesii)

Giddy from this accomplishment, I turned to the Acanthus mollis, sometimes known (but by whom, I am unsure) as bear’s breeches. This is a plant that I like in theory. I cannot say for certain whether I like it in practice, because for me it has never lived up to its billing. It has always been sited in what I consider to be part shade, getting afternoon sun (I’m sure it would prefer morning sun, like all other plants on the planet, but we cannot always have what we want). Instead of the 3′ clumps of spectacular evergreen foliage it is supposed to yield, I have 8″ clusters of spectacular leaves, if small, few in number, and in fact deciduous. It has never flowered.

I made a last-ditch attempt to make it happy, transplanting it (in three pieces) to the edge between the white garden and the pink-purple-yellow garden, where it may receive, if not morning sun, then somewhat-earlier-in-the-day sun. I will consider it successful if it produces a larger clump of promising foliage. I will forgive its reticence to flower.

I have heard that it is best to make the commitment to Acanthus at the nursery, because once you bring it home, you will never fully be rid of it. Not that it grows rampantly (clearly!), but the roots are rather brittle and will break easily. If a partial root remains behind, the plant will regenerate from it. I don’t normally show this much faith in a plant, but the leaves are truly irresistible.

This is getting slightly ridiculous

I finished the saloon door gate. It was a big hit with the 7-year-old, who immediately began bursting through one way, then the other. Why, she asked, did we ever take these out of the house when they’re sooo cool?

saloon doors finishedIncidentally, these gates are placed in a break in the new border of azaleas being made by the Great Azalea Migration. In my mind’s eye, these gates will one day offer an enticing  pathway through great billowing flowering shrubs. We’ll see.

In the afternoon, I sowed:

  • Echinacea purpurea
  • Digitalis purpurea
  • Cleome ‘Two Tone Pink’
  • Datura (white, variety unspecified)
  • Campanula trachelium
  • Asclepias incarnata (pink)
  • Asclepias tuberosa (orange)
  • Blackberry lily (Belamcanda chinensis)
  • Gaillardia ‘Arizona Sun’
  • Shasta daisy ‘Alaska’
  • Monarda (unspecified purple)
  • Bachelor button ‘Blue Boy’ (Centauria cyanus ‘Blue Boy’)
  • Peach-leaf campanula (Campanula persicifolia)
  • Golden Alexander (Zizia aurea)

So, adding to the butterfly-friendly theme, the Asclepias, Echinacea, Monarda, Datura, and Zizia aurea should reel them in. Maybe more of them will as well; I need to read up.

If I had any sod to bust, I would say I had better get to it; assuming all these things grow, my garden will absolutely explode with plants next summer. As it is, I had better start busting clay and place an order for about 12 yards of manure. It may take me from now to the last frost to prepare good beds for all these fellas.

Rain delay

The Great Azalea Migration has been halted temporarily until I can find a place to put the remaining chunks of shrub. In the meantime, several days of heavy rain yielded some very interesting mushroom life in the garden. I don’t know what varieties these are, but I think they’re so interesting to examine.

I think this one is my favorite:

And finally, while this didn’t spring up overnight, I love its intricate pattern of color and texture.