About 4-5 years ago we had a large cedar tree removed from our yard. About 1.5 years later, a professional company planted blueberries, chinese fringe flower, daylilies, manzanitas, blue fescue mounding grass in the same area with wood mulch. After 3 years these plants are alive but they have hardly grown in size despite being watered on a drip system and nearly full sun. Could it be that the cedar sawdust and chips left behind have made the soil inhospitable to growth?
The soil under cedar trees is very acidic. That is most likely an issue for you.
Cvile_ gardener is right, your soil MAY be too acidic for the plants in question, best thing to do is buy a very cheep Soil Testing kit from garden store, they are very easy to use, following the instructions, you will see what PH your soil is (test various areas as there can be different PH readings) the kit will
also tell you what deficiencies your soil show when growing the plants you have.
I have looked at the picture and the plants do actually look healthy, my one big concern is that there is a full flourishing thick hedge growing more or less side by side, this hedge will be taking up practically every bit of water that comes within reach of it, it will also have roots stretching further afield to search for moisture, I am off the opinion that the drip system is not supplying quite enough water for the plants as the competition is way too much for the small plants.
I dont think light is playing any part in the problem, IF that were a problem, your plants would be growing upwards or sideways trying to grab better light, so that to me is not a prob.
Have you gave any feed to these plants, I would tray a half strength Multi purpose feed OR if you can, scrape away some of the mulch and sprinkle a handful of Blood / Fish / Bonemeal around the root area, this is a slow release fertiliser, NO chemicals and as it's slow release it should lasy all season. you can buy this from Garden stores in a packages, read the dosage as it is dangerous to apply too much feed, after scattering the feeds (Whatever you choose) make sure you fork it into the soil around the root area, I would use HAND fork as you dont want to damage any roots under the soil., water well and this will help take the feed down to the roots where it's required
re-spread the mulches back to where they were. just keep an eye out after doing the feeding etc, stick your fingers down into the soil every other day to check the plants are actually getting moisture lower down where it matters for their growth and health.
Hope this gives you other areas to consider and you get things sorted out. enjoy your garden and let it grow with you.
Kindest Regards.
WeeNel.
Blue berries require acidic soil not sure about the others.
