Congratulations on the new house!!! You are definitely getting to work on the yard much much earlier than I had a chance. I think it took me a year before I could even start planning outside projects!

Can you find out from the previous ownder the variety of these rhododendrons and if & when the shrubs were pruned? The variety can tell us when are they supposed to bloom, etc. Information about the prev owner's pruning time can help determine if the shrubs are begin pruned right after the flower buds form.

In the meantime, maintain the soil moist as much as possible to prevent dry/non-dry soil periods that might stress the plant. The flower buds are also sensitive to lack of water so try not to let the plant dry out for too long. Mulch with 3-4" of acidic mulch to reduce the amount of water needed. If the soil feels dry (or almost dry) when you insert a finger to a depth of 4" then you need to water.

I would not prune now as you want to do because flower buds develop in the Fall and stay on until the proper blooming time in Spring. So if you were to prune now, you would be cutting off the blooms. If you lack identification about this variety, the safest to thing to do when pruning is to prune two weeks after blooming stops prune. Since flower buds begin to develop around July-ish, the latest you should prune is somewhere around June.

Luis

I've read in an Ed Hume book if rhodies not blooming 85% chance that soil level too high so I'm questioning comment about mulching with 3-4" of mulch -- wouldn't this raise the soil level too high and cause it to not bloom even if healthy plant?

I'm asking this because I have some rhodies that look healthy but don't bloom (the soil level was higher than the root mound - I removed excess soil and soil in area not great quality so would like to improve it), would like to add some compost to improve soil (they're in ground so compost would be done above ground) but am concerned about raising soil level to where they won't bloom.

Thoughts?

Wayne, mulching is not adding to the soil depth. Mulch decomposes.

rswcpa, do you know if the shrubs were getting adequate water during those dry months? They could be reflecting drought rather than too much sun. If you do choose to move them, evaluate how dense the shade might be under the redwood canopy. Is it dappled there or more solid - the shrubs need some sun to bloom and perform well....best condition is protection from hot mid day sun or placed in dappled shade in warmer climates.

You mention yellow leaves, but that may indicate many different problems. Check these:

Yellow leaves with green veins indicate a nutrition problem with not enough iron. It is usually caused by a high pH but can also be caused by poor drainage, planting too deeply, heavy soil with poor aeration, insect or fungus damage in the root zone and lack of moisture.

Small yellow leaves and stunted growth are signs of water stress brought on by water-logged soil or wet/dry fluctuations in soil moisture.

Yellow mottling on the upper surface of leaves and black sooty mold and transparent insects on the bottom are symptoms of Azalea Whitefly (Pealius azaleae.) and Rhododendron Whitefly (Dialeurodes chittendeni.).

Yellowing of leaves surfaces, often with brownish burned areas, occurring on leaves that are more exposed to sun, is caused by more sun exposure than the plant is able to tolerate. Some varieties need shade, while all plants that have been protected from direct sun will be tender until hardened off by gradual exposure to sun light. Possible solutions are to give the plant more shade or move it to a more protected site.

Uniformly yellowish-green leaves is often just the need for more nitrogen. This will be more noticeable in the full sun. Some less sun tolerant varieties will always be light green in full sun.

Yellowing of leaf edges has been noted in gardens where sandy soil conditions or root competition with other plants caused insufficient soil moisture and nutrients. Usually incorporating organic material in the soil and removing the plants with the competing roots solved the problem. Care must be taken not to disturb the roots of the rhododendrons and azaleas. Hence it is best to prepare the soil adequately before planting. The tops of most competing plants can be removed leaving the offending roots in the ground and the offending roots will simply decay and pose no problem.

Here is a link that might be useful: How to care for rhododendrons and azaleas.