Help with reviving my rhododendron, please.

[very_green]

Greetings from Oregon!

I have a rhododendron which was not doing well at all, to say the least. The leaves were sparse and spotty and the flowers didn't look so hot either. I took a leaf with me to the nursery last year. "Sunburn", they said.
I cut off all the completely dead branches (leaving the ratty ones that still had live leaves on them, because...I just chickened out). I was fully prepared to dig up the whole thing and replace it with a hardier version, that could handle more sun, but lo and behold, now there's all this new, healthy growth (except for a couple of leaves burnt at the edges) and gorgeous flowers. The new growth has reached over half the size of the old growth at this point and digging it up and replacing it now feels like a sin, sunburn or not.
I intend to cut down the rest of the ratty parts after the plant has gone dormant (I shouldn't do it before then, right?) and see how the thing grows up.

Strangely enough, the soil tests as alkaline. I've taken two, maybe three tests, and that's what it came up as every time. So I'm not sure how it can grow so well.

Should I fertilize it or is it too late in the year for that? I have Lilly Miller's Rhododendron, Evergreen & Azalea food and Miracle-Gro's water-soluble
Azalea, Camellia and Rhododendron plant food.

There's no way of acidifying the soil quickly, is there? I just really want to do whatever I can to help this plant get back on its feet...roots. Any recommendations?

Sorry about all the questions! I'm very new at all this.

[Kisal]

Rhodies should be pruned immediately after flowering. They set the buds for next year in July to August, so if you prune after that, you'll cut off the next year's flowers.

No more than 1/3 of the living part of the shrub should be removed in one season. You did well to leave the sunburned leaves, even if the plant looked scraggly. I allow about 3 to 4 years to rejuvenate a rhodie or azalea.

You can give it some fertilizer now, but don't feed it later than mid to late August. You don't want it putting out new growth late in the year. I use the Lilly-Miller brand. I don't have any experience with the Miracle Gro brand, so I can't say whether it's better or worse than any other.

I'm rather surprised to hear that your soil is alkaline, but I don't know what part of the state you're in, either. If you're using a home soil test kit, I
wouldn't trust it, but that's just my personal opinion. You might want to have a lab do a professional test for you. I recommend that you contact your nearest Extension Service office and ask them for suggestions about where to have a soil test done. With a professional test, you'll get more dependable results, and the staff at the Extension Service can offer good advice on the best way to amend your specific soil.

HTH!

[applestar]

Rhododendrons like a good amount of water, but they don't like waterlogged location. In my clay subsoil garden, I planted on a big mound at the base of a downspout (and I still have to water during drought)

I actually don't fertilize my rhodo at all, though that's not the typical advice -- it still grows and gives a full showing of flowers though. I like composted pine bark mulch, which I think does help to acidity the soil, but the hydrangea nearby still flowers pink.

I believe cutting back the weakened branches (as long as there are other healthy branches) will stimulate new buds to break and grow, and if you provide good care over this growing season, it will fill out.

Watch out for lace bugs on struggling leaves (leaves curl under and brown specs and sticky residue form on the underside).

[very_green]

Thank you both so much for the advice! I do use a home-test kit (or two different ones, to be exact), but I do know that can be unreliable (I was thinking about getting an electronic PH meter for a while until I saw how frequently they got bad reviews), so I will see about getting a lab test done.

I live a half-hour drive East of Portland.

If my rhody turns out to have lace bugs, would buying lady bugs help? I'm a little wary of chemicals.