How to take care for your hibiscus
The hibiscus plants you can purchase in the garden centers, supermarkets and shops are mostly treated with growth retardants and that is one of the reasons they die on you within a few months. As less treatment they received as better the chances are that they might outgrow the treatment after 6 to 9 month, will then start with a normal bushy growth. There is a possibility to help the plants to outgrow the growth retardant. After you have purchased such a plant take it immediately out of the pot, wash the soil off the roots and repot it in quality soil mixed with Perlite and give it the double amount of fertilizer. Be careful not to over water!
You can keep most of the plants small by pruning them, they will still flower nicely and it will not effect the size of the bloom.The hibiscus offered from special nurserys are never treated with hormones and are therefore much healthier, most of them are grafted anyway.
To take care of hibiscus is very easy: they like moist, but not wet soil, particularly young plants are very root sensitive. The soil should be mixed with Perlite 2:1 to keep it airy. From March till September the hibiscus should be fertilized (double strength) with every watering, October/November in a fortnight normal strength. No fertilizer in December/January, February once a week. Use a fertilizer which is low in phophorous but high in nitrogen and potassium, containing as well all the minors. In summer time you can do a foliar feeding with a fertilizer high in phosphorous.
Always keep in mind that the pH for hibiscus should range between 5,5 to 7.
As the plants are originally coming from the tropics and subtropics they like the sun. Placed on a sill facing the south they need some shading in summer during midday. On the balcony, porch or garden they like a sunny place, but still do well with a bit of shade for a short time. By the end of May you can bring the hibiscus outside, they will shed a few leaves and buds, but recover quickly. In autumn, when the temperatures drop to only 8°C/45°F the plants should be taken indoors again. Don`t worry if the plants drop a few leaves and buds again. Hopefully the summer was very sunny and the plants will show another explosions of blooms till Christmas. During the wintertime very often spidermites, white flies and aphids appear on the plants, but they are easily destroyed with a miticide and an insecticide, with Neem oil all of the pests get killed. It’s best before bringing the plants into the house to spray two to three times within 10 days to kill all pests in their different stages of development. This way you can keep your hibiscus pest free till spring time when they can be placed outside again.