Abies veitchii 'Heddergott'

Abies veitchii 'Kramer'

That type of yellowing is usually a signal for poor drainage and wet feet. Firs may be the most sensitive if it's not occurring within other Genus'.

Dax

last pic.. older needles.. normal fall needle drop ...

i cant make heads nor tails of pic 2 .... since i dont know the plant... nor its normal coloration ....

pic 1.... rather minor.. though i am sure shocking to you.. coloration... i would ask what the buds look like on the affected parts ... the future is ALL in the buds ...

i am not dismissing dax's suggestion ... i am offer other observations...

ken

The middle one looks more like sunburn as it's on all upper surfaces but the yellow is uniform like a water problem as Dax said. On spreading firs the top growth is weaker than the side growth and that's what is mainly affected on yours by it's diminuative branch size as well as colour. My abies nord. 'Muensterland' still has the odd yellowing minor upper branches wheras the majority is very healthy.

I would double check the drainage and go easy on the watering and also I would start to take out the inner congestion of your top two specimens as there is a lot of competing growth. Use fine nosed clippers and work through taking out all branches that are weak and redundant. You want to leave only the branches that hold enough bud growth to keep filling in. Especially take out branches low down inside that are dead and brown so that there is free air around the trunk. It'll be a good third of your plant gone, it'll look gappy but that will leave plenty of air circulation and your plant will be much more healthy long term. It looks drastic at first but they fill in very rapidly afterwards.

This post was edited by severnside on Sat, Oct 18, 14 at 7:57

To give you an idea here's a before and after shot of my Abies concolor 'Piggelmee'. It looks full and healthy in the first but there is a lot of competition going on. Branches that are and will clash and a general matting of foliage together. In the second pic it looks drastically reduced but all those branches are primary and full of strong buds. Next season's growth will fill all the gaps. I'll repeat the process to a lesser extent as and when.

Before

After (recently planted out, please excuse the weeds)
See how much the air can circulate compared to before.

I'm *not* sure what is going on with these plants.
As a general observation though: "The 3 of them did great all summer with the heat and high humidity. I noticed this started to happen when the temperature fell into the 40s at night about 3 weeks ago. "
When plants are suffering from root problems, there can be a delay, sometimes quite long, until it shows up on the rest of the plant.

Thanks everyone for responding. The firs didn't get in worse and the buds on them all look good. I'm going to try what severnside suggested, and see if more airflow impoves the health of them.

Nick