Wrong no the high nitrogen!! To get hibiscus to flower more than they grow, use a 2-10-10 granular. Otherwise, they grow more than they bloom. No extra potash needed. They only need be fertilized three times a year, October, March, and July.

Different strokes for different folks. I use 15-9-12 9 month formula osmocote on the soil and 20-20-20 Peters water soluble. I'm extremely pleased with blooming on my plants. I used to sell hibiscus retail and my plants always went quick.

From what I've read in the past, experts recommend a 2-1-3 ratio in fertilizer for hibiscus.

randy

Randy, I'd agree that from most of my recent research on various retailer sites, they're all recommending the low phosphate formulas for better flowering, so I guess it's time to pay an extra shipping charge and to order some to try for the first time. I'm tired of getting so few blooms, though I must say because of the winter light change when they're brought in , I comprosmise a lot with the summer sun, since they can burn so badly when moved outdoors in too much sun for the summer. I've always thought they do prefer a fair amounth of sun to flower best, and mine get very little during their shady summer stay outdoors.

You have just told me why your plants don't bloom. It's not about fertilizer at all, they don't get any sun.

I would encourage you do not be afraid of summer sun. I see you live in Michigan. I have a hard time visualizing hot summer sun in Michigan :-). My large hibiscus are placed in areas in the growing season where they do not receive any shade until until 6:00 or 7:00 pm in the afternoon.

Your problem is not too much summer sun, it's not acclimating your plants to the move outdoors. You should place your plants in complete shade at first. Allow them to adjust to the outdoors for a period of days. Then move it to a location for a few hours of morning sun. After about a week of that move it to a half day. After a few weeks, move to full sun and your plant will reward you with nice tight internodes and massive amounts of blooms. That is if you feed them often enough.

I even have to acclimate my plants from the greenhouse to the outdoors in the spring. They are not used to the wind.

randy

I must confess, that I know they need hardening off in the spring least they burn up , but it seems mine even after weeks of hardening off still want to burn even in Michigan, though most likely any of those weaker leaves that burn would be shed and then would be followed by more sun tollerant leaves. In fact some older foliage on some types of tropicals never will acclimate to full sun though the newer leaves do, but in hopes of the reverse not making them shed in fall going from bright light to much lower light, I just picked a sort of middle ground so the new leaves dont' demand so much light without going into shock on their return trip indoors. I find that even the growth on my bougainvilleas , which gets five or six hours of sun starting in late afternoon, goes into a fast decline within a week of comming back indoors, and nearly all leaves are shed in a little over a couple of weeks. As I recall, most of the hibiscuses in California were growing in nearly full sun to part sun, so I know the extra sun will help with flowering. Next summer I will bite the bullet and not worry about burnt leaves so much and hopefully that will make a difference.

Shedding leaves is a natural process. In native or naturalized habitat both plants you mention shed old leaves, but not at the pace of plants that receive a harsher climate change during the season like ours do.

Even evergreens drop old leaves and needles.

I prefer my plants drop leaves in the winter and rest some. They preform much better in the summer when treated that way.

randy

I must say that years ago I saw several gardening shows that mentioned keeping tropical hibiscuses "dormant" for the winter, but to my way of thinking some plants don't really have a true "dormancy" period and are best kept growing , though at a much slower pace, even through the winter months indoors. I guess they'd give them a severe prunning and cut back on the watering to barely moist soil, and just give them a cool room for the winter, and I know some other folks that take that approach to keeping their tropicals indoors for the winter. I just dont' have such a cool winter location indoors to take that approach. As for the shedding of leaves, it surprises me how alarmed some folks are to see many types of tropicals shedding the oldest leaves, since it is completely a natural process barring loss of the younger leaves, which may be a sign of ill health and insects and disease.

I used to kill hibiscus left and right, up until I started buying a special hibiscus blend fertilizer..now my tree hib is 11 yrs old and doing great..I buy at www.plumeriapeople.com or www.stokes-tropicals.com
You sprinkle the pellets and water. They're meant to last 3 months, but I reduce by 1/3 and feed once a month.

As for Hibs going dormant in winter, I think they do to a degree..it depends on the light..My hibs sit in front of a south and near east windows. They bloom more in summer but don't stop in winter. At night, I keep a small light to the side, so this helps, too. They're misted daily, and soil is left to dry before watering. I also use Superthrive.
I've 4 hibs now, and another on the way..Next spring/summer I'd like to get one w/yellow flowers, and one w/fragrant flower. That will complete my hib collection. Anyway, does anyone know if this acidic substrate will harm the plant? Thanks, Toni

Sun is important. I have grown mine in full sun here in Maryland in the summer with no leaf scorch, except occasionally when I move them outdoors too quickly in the spring. I do find that on some of the sunniest, hottest days, they will wilt in late afternoon but they bounce back quickly.

I use Space City hibiscus food, available at yardgeek.com. But I fertilize VERY sparingly in winter, even though my plants have decent light indoors. In the summer, I push the fertilizer more frequently according to the directions on the package and get lots of blooms.

If you don't want the hassle and expense of ordering special food, any fertilizer with a lower middle number and roughly similar first and last numbers should be fine. I have read that the "bloom booster" fertilizers (with the high middle number) lead to a build up of the middle number over time and actually inhibit blooming.