Tropical hibiscus 'Diamond Head'

Tropical hibiscus are highly sensitive to phosphorus (the middle “P” number on fertilizers) and an excessive amount will kill the plant. Do not use so-called “bloom fertilizers” on them. Instead tropical hibiscus need a lot of potash to bloom properly (the last number or “K” on fertilizers). Palm fertilizers are widely available and usually have the proper ratio of a medium-low-high NPK ratio along with needed minors.

The pesticide malathion will defoliate tropical hibiscus. Do not use it for pest control.

Try to plant in a location that enjoys full sun and remember to water moderately. Keep in mind when planting that Diamond Head is thought of as tender, so remember to wait until your soil is warm and the night time temperature is well above freezing before moving outside.

By our calculations, you should look at sowing Diamond Head about 84 days before your last frost date.

Ensure that temperatures are mild and all chance of frost has passed before planting out, as Diamond Head is a tender plant.

¹ gardenology.org/wiki/Hibiscus_rosa-sinensis