Honeysuckle leaves turning purple, yellow, then dying

Question

I'm in England's South Coast, with a climbing honeysuckle (can't recall exact kind) planted in the back, north-facing garden, against a waist-height east-facing fence. It gets full sun most of the day, and has white stones around the base to provide some root shade and retain moisture. Watered most days at the moment due to extended dry weather, fed weekly with Phostrogen.

The whole plant is shown here:

The base has become very woody and fragile, see zoomed in picture here:

New leaves appear healthy and green, like this:

However they soon turn purple and eventually yellow, then wilt and die, such as in these examples: Many also display tiny orange blotches, but I think that's from the neighbour painting his side of the fence.

The leaves show no signs of pests on either side (the occasional ant, but no aphids) an no residues on the leaves that I can wipe or scratch away.

I've searched extensively online. All I can find regarding honeysuckle and purple leaves is due to powdery mildew. However from photos online, it doesn't look like that to me.

I do notice there's a thin pale film on the shoots, but I'm not sure if this is normal. See picture below (darker, red area on the stem is where I wiped the film away with a finger).

I hope the images help. I really don't want to lose the honeysuckle if I can avoid it, so any suggestions are welcome.

Answer 1

It may well have a problem with mildew and/or rust - on honeysuckle, it doesn't always show up as obvious powdery deposits. However, there are some environmental/cultural issues that will likely be affecting it. First, honeysuckles like partial shade; they don't like being very close to a fence and should be planted at least a foot away to improve air flow; they benefit from organic mulch round the roots. As it's been so sunny and hot, those white stones will have been reflecting a lot of heat and light up the plant - remove those and replace with organic mulch, such as wood chips or preferably composted animal manure, ensuring that the soil underneath the stones is nice and moist before applying the mulch. This will slowly decompose and improve the soil round the roots of the honeysuckle as it does. Stop feeding with Phostrogen weekly - this is too much nitrogen and will cause the tips of the plant to be soft and sappy, and that will encourage mildew problems. The best way to fertilize is simply to apply a handful or two of something like Growmore granules in April each year, with another dose 6 weeks later if you want (it's not essential, one application a year will be fine), raked lightly into the soil round the base.

If things don't improve, you may need to try treating it for mildew; you can try a spray of 2 parts milk to 8 parts water, but this is more effective as a preventative rather than a treatment, so you may need to seek out chemical measures, such as Provanto fungus fighter concentrate. The orange spots might be rust, and this is another affliction that prefers over fed, soft and sappy growth; you can try a fungicide that treats for rust to see if it helps, though the Provanto fungus fighter might do the job.