Hibiscus

[1voyager1]

Since the eruption, the non natives are doing much better than before.
I'm thinking the SOx gasses have acidified the soil to, their liking.
Plus, I'm guessing that the SOx gasses have also taken a toll on the vermin that feed on them and other plants in thr yard.

1.
The Chinese Red, H. rosa-sinensis, had become infested with a hibiscus mite before the eruption.
I pruned it back severely just before the eruption began.
It had galls all over its leaves and flower buds disfiguring it badly and affecting its ability to produce flower buds.
Right now, the plant is mite free, growing nicely and beginning to bloom again.
I expect it will become infested again.
Is there a non pesticide way to control the hibiscus mites?
Are predatory mites available locally?

2.
The prior owner had a Pink, what looks to be a Rose of Sharon, H. syriacus growing when we bought.
It looked to be on the verge of dying for 5 years.
Since the eruption, it has grown a nice healthy set of leaves and is now blooming prolifically.
I'm inclined to think the SOx gasses acidifying the soil may be the cause.
Any other thoughts on the cause?

3.
I bought the H. brackenridgei at a Master Gardener plant sale several years ago.
It has never done well.
Still doesn't seem to be doing all that well.
Supposedly, it is found on the lee side of the island.
my assumption is that we're too wet for it to be happy here.
Thoughts?

[dan d]

Call master gardeners belp line? I think you are on the right track for acid soil tho.
Aloha

Dan D
HPP

[kalakoa]

Treat mites with aggressive pruning followed by sulphur.

Brackenridge did "okay" here but I'm not sure it survived extended neglect (haven't been out that way recently).

[kalianna]

Neem oil works well too but spraying a large hibiscus does take some time.

[spencerw]

so heres my take on the eruption on the plants. i live in leilani, have for 3 years. our property is 1 mile north west of fissure 8. i went to the property every two weeks during the eruption and been there almost every day since shes stalled.
everything (besides the grass) is more vigorous and growing more healthily than ive ever seen them. its almost as if someone went and fertilized every single plant on the property. even plants that ive never cared for are blooming and growing like never before. and dont let me go on a rant about our native forest, but also more vigorous than ive ever seen it.
anyway, heres my theory; due to so many things being defoliated and some plants dying completely, this acted as a pruning and mulching leaving so much debris on the ground. the acidity of the rain broke down many logs, leaves and other things on the forest floor, quickly deteriorating and turning into soils. i can literally go into an area and clear it in an hour, when it would have taken me 4-6 hours pre- eruption to clear. i can go and just mash everything to the ground including large dead ohia trunks. this in turn mixed with the above ground abuse from the emissions putting a temporary hold on the plants growth, somewhat like a winter, and now its 'early spring' and everything is growing trying to catch up for lost time. this mixed with all the rains we had, lack of pests, nutrients from ash and volcanic behaviors has put most plants in extreme grow mode.

make sure you fertilize your brackenridgei well. also make sure youve got lots of cinder in the soil mix to promote good drainage because it is a dryland plant. however, i know plenty of people growing it in very rainy places.

as for your acidic soils, whats your landscape like? in the native soils my ph is near 4.5 this was pre eruption. unless youve been liming your soils its pretty safe to assume they were very acidic in general. some plants prefer more and some prefer less acid. but most tropical things thrive in acidic soils

[bananahead]

all of our native endemic red hibiscus are resistant to spider mites compared to the Chinese Hibiscus...

Hibiscus clayi
http://nativeplants.hawaii.edu/plant/vie...scus_clayi

Hibiscus kokio
http://nativeplants.hawaii.edu/plant/vie...okio_kokio

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save our indigenous and endemic Hawaiian Plants... learn about them, grow them, and plant them on your property, ....instead of all that invasive non-native garbage I see in most yards... aloha

[1voyager1]

@ bananahead,

Both of those links state:
" ... The native red hibiscuses are just as prone to attract the hibiscus erineum mite as the non-native red hibiscuses."