Tropical hibiscus 'Blue opal'

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. Blue opal is generally regarded as a half hardy plant, so it will need protecting in periods of cold weather.

Blue opal is half hardy, so ensure you wait until all danger of frost has passed in your area before considering planting outside.

¹ International Hibiscus Society Registration for Blue Opal

² Hidden Valley Hibiscus information page for Blue Opal