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.

Use this plant food for your Canistel tree:
SUNSHINE C-Cibus - Crop Nutrition Booster

2. Apply micro-element remedies that are very effective for improving fruit production, especially when flower or fruit drop occurs:

SUNSHINE Honey - promotes more efficient blossoming and pollination, makes flowers bigger and reduces bud drop.
SUNSHINE SuperFood - improves plant vigor and quality and size of flowers These are all natural, eco-friendly supplements that work great for fruit trees and other edibles.

🌿 Bring the Jungle Inside: Winter Survival Guide Part 1: Lighting ❄️

Smokey: "Winter lighting must be precise. I need this light exactly at 14 inches."
Sunshine: "Sure. I am holding this… little number thing."
Smokey: "It reads humidity. Your main job is to look cute."

🌞 LIGHT, TEMPERATURE, PLACEMENT

Winter indoors is a different kind of battlefield. Dark rooms. Dry air. Cold windows. Random drafts. Weak light. Sad plants. We've been talking about keeping your tropicals alive outdoors previously. But some of you have no choice this time of year. You have to bring the jungle inside.

If that is you, then this is your plant survival guide.

☀️ LIGHT: THE WINTER LIFELINE

Light advice here comes straight from our in-house expert, Michael Dubinovsky, a high-tech lighting engineer with over 30 years of hands-on experience. If he says brightness beats hours, trust him.

Here is the truth: Indoor light in winter is 10 to 50 times weaker than outdoors. Short days. Low-angle sun. Windows filtering half the useful light. It all adds up.

Tropicals need 10 to 12 hours of real brightness. Winter sun cannot do that on its own. Not even in a big window. So we help them.

Use bright LED shop lights or utility lights. 5000K to 6500K CCT. High lumen output. Skip decorative bulbs. Skip purple grow fancy toy lights. If you want a single plant light, even a clamp lamp is fine if you screw in a bright daylight LED bulb.

Panels work best for plant clusters. Bars for shelves. Bulbs for single plants. And grouping plants under one bright panel always beats spreading them out.

Distance matters: keep LEDs about 12 to 18 inches above the leaves. Too close: leaf burn. Too far: stretching, weak stems.

Leaves reaching up? Light is too high or too weak. Leaves curling down? Light is too close.

If you want a reality check, download any smartphone lux meter app. Most indoor corners are 50 to 200 lux without supplemental light. Tropicals want much more

And a quick tip about windows: winter sun comes in sideways. A spot that looks bright at noon can go dull by 2 PM. Don't count of window light

Bright light or long hours

People try to fix weak light by running it for 16 or 18 hours. That does not work. Plants care more about light intensity. A few hours of strong light beats all-day dim light. If the light is weak, adding more hours will not change anything except your electric bill.

Simple rule: Short duration but bright is always better than long duration but weak. - by Michael, Top Tropicals lighting expert

No need for fancy horticultural panels

You do not need purple grow lights. You do not need special horticultural fixtures. You do not need expensive panels unless you want real winter growth.

For winter plant holding till spring, the inexpensive solution works great:

• Bright LED daylight bulbs (5000K to 6500K) from hardware store
• High lumen output
• Inexpensive clamp lamps
• Aim directly at the plant from 12 to 18 inches

This setup keeps tropicals happy until spring without buying anything fancy. Save the money for soil, pots, or your next plant.

Indoor plant lighting safety note:

• Use timers. Keep cords dry. Do not overload outlets.
• Do not hang lights over humidifiers.
• And do not put fixtures on piles of books to raise them. People do this.

✔️ WINTER INDOOR FAQ: TEMPERATURE AND PLACEMENT

Q: I am in Home Depot. Which light do I buy?
A: LED shop light, daylight color (5000K to 6500K), high lumens. Skip fancy plant bulbs.

Q: Can I use clamp lamps or floor lamps for plants?
A: Yes. Clamp lamps with a bright daylight LED bulb work great for winter holding.

Q: Do I need special horticultural grow lights?
A: No. A bright LED daylight bulb works fine for winter. Save the fancy lights for real growth projects.

Q: How far should the light be from the plant?
A: About 12 to 18 inches above the leaves. Too close burns. Too far stretches.

Q: Can I run weak lights for 18 hours to compensate?
A: No. Weak light plus long hours still equals a weak plant. Brightness matters more than hours.

Q: How do I know if a spot is bright enough?
A: Use a free phone lux app. Most indoor corners are much too dim for tropicals.

Q: I have a huge window. Why do I still need LEDs?
A: Indoor winter light is weak, short, and filtered by glass. Plants want intensity, not just a big window.

Q: My window faces north. Now what?
A: North windows are decorative only. Use supplemental lighting or move the plant.

📚 Learn more:

• How to overwinter tropical plants indoors
• Overwintering Adeniums outside of tropics

😼😺 The Story Behind Smokey and Sunshine 🐾

Some stories are easier to tell with a little humor. Smokey and Sunshine were never just mascots. They represent the two forces behind every decision we make here: bold ideas and careful reality. One dreams big. The other checks the climate zone map. Together, they remind us that growing plants is part science, part optimism, and always personal. If you have ever wondered why they keep appearing in our newsletters, you can read their full story on the Smokey and Sunshine page. They have been with us longer than most people realize.

🐾 Learn the Story of Smoky and Sunshine

Freeze Testing of Grumichama and Cherry of Rio Grande 🍒❄️

When temperatures dropped to 25F, with wind chill near 14F, winter made it clear which tropical trees were truly resilient. Some plants burned back. Tender growth collapsed. But our established Eugenia cherries stood steady. Leaves held. Branches stayed flexible. The canopy remained intact.

Cherry of the Rio Grande (Eugenia aggregata) and Grumichama (Eugenia brasiliensis) are among the most cold-hardy tropical cherries for Southern gardens. Both are native to Brazil and thrive in USDA Zones 9b–11, and even protected 9a sites.

Cherry of the Rio Grande produces dark ruby fruit that ripens almost black, with a rich, full cherry flavor. It flowers early in spring and can fruit well into summer. Mature trees can tolerate brief drops into the low 20s once established. Trees typically grow 8 to 15 feet tall, remain naturally compact, and often begin fruiting within 2 to 3 years.

Grumichama is an evergreen tree known for both beauty and productivity. In spring, it covers itself in white starburst flowers that attract pollinators. Within about four weeks, glossy purple-black fruit develops. Established trees tolerate temperatures into the upper 20s and grow well in the ground or in 5–10 gallon containers. Mature trees can produce hundreds of fruits per season.

Across the Eugenia group, strengths are consistent: early bearing, compact growth, heat tolerance, light freeze endurance, and low pest pressure. They are adaptable to different soils, need modest water once established, and perform in full sun or partial shade. Birds enjoy the fruit, but there is usually plenty to share.

Nutritionally, Eugenia cherries provide Vitamin C, fiber, antioxidants, and notable Vitamin A that supports eye health. They offer sweetness with real dietary value.

In the kitchen, they are simple and rewarding. Cherry of the Rio Grande makes an easy compote. Simmer the fruit with a small amount of water until soft, mash lightly, and spoon over pancakes or warm bread. Grumichama turns into a deep red jam with sugar and lime, or can be blended into a bright spoon drizzle over vanilla ice cream.

Even when not fruiting, both trees remain attractive year-round with glossy evergreen foliage and clean structure. They fit well into edible landscapes, small yards, and container gardens.

Winter will return. The difference lies in planting fruit trees that can handle heat, humidity, and the occasional cold snap. If you are building a food forest for lasting harvests, cold-hardy tropical cherries like Cherry of the Rio Grande and Grumichama deserve a place in your garden.

🛒 Plant hardy Eugenia cherries