D1 Durian

Have you ever wrestled a porcupine that smells like onions and tastes like heaven? That is the paradox of growing the King of Fruits. Specifically, I want to talk to you about the D1 Durian, known scientifically as Durio zibethinus and locally in Thailand as ‘Kradum Thong’ or “Golden Button”.

Most Americans only know the Monthong variety found in frozen packets at Asian supermarkets, but the D1 is a completely different beast. It is the secret weapon for impatient growers.

To eat it is such an indescribable pleasure that it is worth a voyage to the East to experience it.

Why do we bother growing this in San Diego? It is admittedly an uphill battle against our desert climate. However, the D1 variety offers a loophole. It is an early-season bearer, smaller in stature, and significantly less finicky than the notorious Musang King.

Through our work with Exotic Fruits and Vegetables farm, we have discovered that D1 is the “gateway durian” for Southern California growers who are willing to invest in controlled environments. If you want a durian that fruits in 4-5 years rather than 8, this is your cultivar.

Understanding the D1 Identity

The D1 is not a shelf-stable commercial giant. It is a boutique fruit. In its native Nonthaburi province in Thailand, growers prize it for its intense sweetness and incredibly smooth, fibrous-free flesh. Unlike the pale yellow of a Monthong, the D1 boasts a deep, golden-orange meat that looks like heavy cream.

Alexander Mitchell

The fruit itself is small, usually weighing between 2 to 4 pounds (1-2 kg). This size is actually an advantage for us here. A smaller fruit load puts less stress on a young tree, which is crucial when you are growing in a container or a high-density greenhouse setup.

The Flavor Profile

Imagine a vanilla custard mixed with almond paste and a splash of sherry, wrapped in a savory onion skin. Does that sound confusing? It should. The D1 leans heavily into the sweet, floral side of the spectrum, lacking the bitter “numbing” aftertaste found in Malaysian varieties like D24.

It is approachable. I often call it the “Introvert’s Durian” because it is gentle on the palate but still possesses that signature funk.

D1 durians are classified as “early maturing”. In optimal tropical conditions, they are ready for harvest 90-100 days after flowering, compared to 120+ days for other cultivars.

The San Diego Challenge: Creating a Microclimate

Let’s be real for a second. Can you throw a durian seed in the ground in El Cajon and walk away? absolutely not. Durian is an ultra-tropical species. It starts suffering tissue damage at 45°F and will die outright if it hits 40°F for more than a few hours. Our San Diego nights, even in summer, can dip too low for a durian to thrive comfortably without help.

Growing a D1 here is like trying to keep a polar bear happy in the Amazon, but in reverse. You are fighting the dry air. Durian trees require a relative humidity of 75% to 80% to transpire correctly. When the Santa Ana winds kick up and humidity drops to 12%, your durian leaves will crispy-fry within hours.

Here at Exotic Fruits and Vegetables, we’ve found that a climate-controlled greenhouse is non-negotiable. I use a dedicated high-tunnel with misters set to trigger whenever humidity drops below 60%. If you are growing strictly indoors or in a sunroom, you need a humidifier running 24/7.

Soil, Water, and Feeding: The D1 Diet

The root system of a D1 tree is a drama queen. It has zero tolerance for “wet feet”. If the soil stays soggy for 24 hours, you risk Phytophthora root rot, which is the Grim Reaper of durian trees. I learned this the hard way three years ago.

I had a beautiful 3-year-old D1 sapling. I thought I was doing it a favor by giving it heavy clay soil to hold moisture during a heatwave. Two weeks later, the leaves yellowed and dropped. The roots had suffocated. Now, I use a mix that drains faster than a colander.

Never use standard potting soil from a box store. It holds too much water. You must mix your own substrate to guarantee drainage.

My Proven Soil Mix Recipe

• 30% Coco Coir: For moisture retention without compaction.
• 30% Perlite or Pumice: Large coarse grade for aeration.
• 20% Compost: High quality, fully composted organic matter.
• 20% Sandy Loam: To add some weight and mineral content.

The Watering Schedule

Forget “water when dry”. That is too vague. You need to maintain “field capacity”. Squeeze a handful of soil; it should feel cool and damp, but no water should drip out. In my greenhouse, I water my 15-gallon containers with exactly 1.5 gallons of water every 3 days during summer (85°F peaks). In winter, I dial this back to 0.5 gallons once a week.

Do not rely on overhead watering for young trees. Wet leaves in a greenhouse environment invite fungal issues like leaf blight. Always water at the base.

Step-by-Step Planting Guide

So, you have acquired a D1 graft. What now? Here is how we handle new arrivals to ensure they survive the transition.

1. Acclimatization: Keep the tree in a shaded area (50% shade cloth) for 2 weeks. Do not expose it to full San Diego sun immediately.
2. The Pot Up: Move it to a slightly larger pot—only 2-3 inches wider than the root ball. Over-potting leads to water stagnation.
3. Stake It: D1 trees tend to have lanky, horizontal branching. Use a bamboo stake to encourage a central leader.
4. Fertilize Weakly: Use a balanced 10-10-10 liquid fertilizer at 25% strength. Durian roots burn easily, so “micro-dosing” fertilizer every two weeks is safer than a heavy monthly feed.
5. Monitor pH: Aim for a soil pH between 6.0 and 6.5. If it climbs above 7.0, nutrient lockout occurs, and your leaves will turn pale green.

Growth Comparison: D1 vs. Commercial Varieties

To give you a better idea of why I prefer D1 for personal growing, look at this comparison table based on my observations.

Harvesting the Prize

How do you know when it is time to eat? Unlike Thai Monthong, which is often cut from the tree unripe and chemically ripened for export, you want your home-grown D1 to ripen fully on the branch. However, you don’t necessarily wait for it to drop, as the impact can split the fruit.

Watch for the “abscission layer”—the knuckle on the stem where the fruit attaches to the branch. When this area swells and a visible line forms, the fruit is days away from dropping.

The smell is your best indicator. A unripe durian smells like cut grass. A ripe D1 smells like sweet, fermented onions and sulfur. My neighbor actually called the gas company once when I was venting the greenhouse during harvest season. That is when I knew the crop was ready.

The Taste Test

I remember the first D1 I harvested. It was about the size of a cantaloupe. I invited the whole team from Exotic Fruits and Vegetables over. We cracked it open along the suture lines at the bottom. The flesh was a vibrant yellow-orange, not the pale white you see in bad supermarket imports.

The texture was like cream cheese. It was sweet, with zero fibrous stringiness. There is a specific joy in eating a durian that has never seen the inside of a shipping container. The flavor complexity starts to degrade 48 hours after harvest, so eating it fresh is a luxury money literally cannot buy in the US.

D1 has a high seed count compared to Monthong. Don’t throw them away! Boil the seeds for 20 minutes and eat them. They taste exactly like chestnuts.

Final Thoughts

Is growing D1 durian in San Diego practical? No. Is it profitable for a small grower? Rarely. But is it rewarding? absolutely.

We are pushing the boundaries of what is possible in our climate. The D1 offers a unique opportunity to taste a cultivar that is celebrated in Thailand but virtually unknown here. It demands vigilance, humidity control, and a lot of patience.

But when you finally pry open that spiky shell and smell that overwhelming, complex aroma, you realize that every high electric bill for the heater was worth it.

Are you ready to turn your greenhouse into a slice of Southeast Asia? The D1 is waiting for you.