Healthy Plants: Q&A from Mr Booster

How to get Canistel tree to produce
without dropping flowers and fruit

Q: My Canistel tree is 3 1/2 years old and is growing very well, see the picture below. It gets hundreds of pea sized "berries" but then they fall off. No canistel fruit. What's wrong?

A: You have such a nice looking tree, it is a shame you can't get any fruit to ripen.
In our experience, Pouteria trees dropping fruit prematurely is a very common problem. There may be one of the following reasons, or a combination of them:
- Cold winters may affect production, and while Canistel is generally pretty hardy tropical plant that can easily withstand short periods of chill, the fruit may never form properly if it had a cold winter.
- Lack of water. Canistel tree is pretty drought tolerant, but for the proper production cycle it needs regular irrigation. Especially during hot summer.
- The tree may be not strong enough; young trees drop fruit very often when they don't have enough "fruiting energy" built up in their system.
Your tree looks well established and vigorous, however, flower/fruit drop is often a sign of insufficient nutrients of particular kind, usually Boron (B) and/or Molybdenum (Mo): either when a tree is too young and not strong enough, or because of poor soils and lack of necessary elements.

Here is what can be done, considering you live in a warm, frost-free climate.

1. Provide regular fertilizing program. We recommend liquid fertilizers Sunshine Boosters that are safe to use with every watering and year around. It is beneficial to switch plants from traditional "slow-release" fertilizer to the liquid one because it makes a huge difference in plant growth and flower/fruit quality and quantity. See also:
- Why liquid fertilizers are better than dry
- Article about benefits of liquid fertilizers.

Healthy Plants: Q&A from Mr Booster

Fertilizing in Winter

Q: I have many tropical plants in my garden, both in the ground and in pots. I realize it is wintertime and some of them, the Hydrangea, Hibiscuses, and roses are in bloom but the rest of them seem wilty and droopy. Is it alright to fertilize them now, or should I wait for a few days? I have an all purpose tropical fertilizer and a 20-20-20 also. Please advise what to do.

A: During wintertime, tropicals may suffer from low temperatures and lack of sunshine which causes droopy leaves, and leaf loss.
Regardless of the cause and plant condition, you should NEVER apply traditional dry fertilizers during cool months. When cold, dry fertilizers (EDTA-chelated) may create nutrient lock up in soil and damage the roots. Dry fertilizers (both granulated and water-soluble) can be used only during hot season - when min temperatures stay above 65F for at least a week in a row, and daytime temperatures are over 75-80F. During hot, active growth season plant metabolism increases. This provides less chance for a chemical root burn, as the nutrients are used up quickly.

However, liquid fertilizers, as long as they are amino-acid based, can be used year round. From our own experience last winter, we discovered that fertilizing sickly looking plants (with signs of cold damage and root issues) with Sunshine Boosters actually revived those plants. Sunshine Boosters even brought back to life some hopeless specimens. Take a look at this gardenia that grows in our garden (picture above). See full article.
In your case, it would be beneficial to use a mild formula of liquid boosters in combination with Sunshine Epi -a natural plant hormone that boost their growth and helps to cope with cold-, temperature- and low-light-related stress.

These are the products we recommend:
- Sunshine Bombino - add to every watering
- Sunshine Epi - twice a month as foliage spray

Since you grow plants in pots, feeding program is especially essential, because plants are limited with a container size where roots can't reach out to more food in the outer soil. In professional nursery set up with injector irrigation systems, container plants are fed daily (depending on season, more than once a day) with every watering. This is why greenhouse plants are so healthy looking.
So feel free to give your plants Sunshine boosters with every watering, dozing according to the label. During cold period, plants need less frequent watering, so fertilizer input will be balanced accordingly, it will depend on temperature and plant metabolism.