Q.

My hibiscus flowers last only one day. Many buds fall off before blooming. What can I do? – Sol Singer, Boca Raton

A.

It is normal for hibiscus flowers to last one day, but bud drop is usually caused by thrips. Apply Cygon according to label directions, and repeat treatment in 10 days. Fertilize with an ixora/gardenia fertilizer to encourage bloom. Do not water plants more than twice a week and not at all if it rains. Hibiscus like a sunny, sheltered, well-drained position to bloom best. Remember that they bloom at the ends of the branches. If they are pruned like a hedge, most of the flowers will be cut off.

Q.

Can you tell me what is attacking my Swedish ivy and gardenia from the enclosed leaves? – Judy Hedgelen, Pembroke Pines

Q.

My pothos has some yellow leaves, but most of the plant continues to look good. Is this a seasonal event? – Muriel Lanz, Boynton Beach

A.

Both Judy and Muriel have similar problems. No leaves are permanent and the lower leaves of all plants will drop off as new ones grow. In Florida, leaf drop with evergreens usually occurs in the spring, but some leaves may drop at anytime.

Q.

I would like to reply to a reader who asked about where to buy saltpeter. One company, Iowa Pyro Supply, 1000 130th St., Stanwood, Iowa, 52337, (319-945-6637) carries potassium nitrate at $2.10 a pound. Shipping by UPS ia about $3.83 for one pound. (The more you buy, the cheaper the shipping.) You have to enclose a photocopy of your driver’s license to prove you are 21 or over. – Stewart Tick, Jupiter

A.

Thank you for your valuable information. This will be helpful for gardeners who want to make their own fertilizer. For those who missed the recipe that we printed before, here it is: Mix 1 teaspoon each of saltpeter, ammonia, baking soda and epsom salts with 1 gallon of water.

Q.

Will I lose my mango tree and fruit if I have the driveway side pruned? The tree is 30-40 feet tall. – Clare Mathews, Davie

A.

Your mango can have up to one-third of the total green volume of the tree removed without putting it in shock. Only use an arborist with good credentials who is a member of the Florida Arborists Association. Avoid hat-rackers and toppers who can ruin a tree. The mango blooms at the ends of the branches, so some fruit will be lost as the tree is pruned back off the drive.