Cycad, Giant Dioon, Gum Palm
Dioon spinulosum

Family: Zamiaceae
Genus: Dioon (dy-OH-awn) (Info)
Species: spinulosum (spin-yoo-LOH-sum) (Info)

Category:

Cycads

Height:

4-6 ft. (1.2-1.8 m)

6-8 ft. (1.8-2.4 m)

8-10 ft. (2.4-3 m)

10-12 ft. (3-3.6 m)

Spacing:

4-6 ft. (1.2-1.8 m)

6-8 ft. (1.8-2.4 m)

8-10 ft. (2.4-3 m)

10-12 ft. (3-3.6 m)

Hardiness:

USDA Zone 9b: to -3.8 C (25 F)

USDA Zone 10a: to -1.1 C (30 F)

USDA Zone 10b: to 1.7 C (35 F)

USDA Zone 11: above 4.5 C (40 F)

Sun Exposure:

Sun to Partial Shade

Danger:

Seed is poisonous if ingested

All parts of plant are poisonous if ingested

Plant has spines or sharp edges; use extreme caution when handling

Bloom Color:

Inconspicuous/none

Bloom Time:

Unknown - Tell us

Foliage:

Grown for foliage

Evergreen

Leathery-Textured

Other details:

Average Water Needs; Water regularly; do not overwater

This plant may be considered a protected species; check before digging or gathering seeds

Soil pH requirements:

5.6 to 6.0 (acidic)

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

Patent Information:

Unknown - Tell us

Propagation Methods:

From seed; germinate in a damp paper towel

From seed; germinate in vitro in gelatin, agar or other medium

Seed Collecting:

Unknown - Tell us

Regional

This plant has been said to grow in the following regions:

Berkeley, California

Encinitas, California

Hayward, California

Huntington Beach, California

La Mesa, California

Reseda, California

San Anselmo, California

Santa Barbara, California

Thousand Oaks, California

Yorba Linda, California

Boca Raton, Florida

Brandon, Florida

Fort Myers, Florida

Jacksonville, Florida

Port Charlotte, Florida

Venice, Florida

Windermere, Florida

Brunswick, Georgia

Greenwell Springs, Louisiana

Beaufort, South Carolina (2 reports)

Bluffton, South Carolina

Hilton Head Island, South Carolina

Sumter, South Carolina

show all

Gardeners' Notes:

6
positives
2
neutrals
0
negatives
RatingContent
Positive

On Sep 7, 2014, southeastgarden from Jacksonville, FL (Zone 9a) wrote:

I have grown this plant outdoors for more than a decade in zone 9a under the canopy of a live oak but without any additional winter protection. It does not show cold damage until winter temperatures dip into the low 20's F. It has been defoliated a few times by lows around 18 degrees but always produces a new crown in spring. It grows very slowly here but looks great most of the time.

Neutral

On Nov 5, 2012, JohnPirate from Auckland
New Zealand wrote:

I bought a bulb 150mm in diameter 2 1/2 years ago and have ot in a pot and feed and water it regularly. There is NO growth, but the bulb looks healthy....perhaps it is thinking what to do.....!

Positive

On Feb 14, 2011, donnacreation from Sumter, SC (Zone 8a) wrote:

This cycad can be grown in zone 8a with winter protection. I pack pinestraw all around and on top of the plant, and then cover with black plastic, secured by stones.

Positive

On Aug 11, 2007, BayAreaTropics from Hayward, CA wrote:

One of the most reliable cycads for the bay area.It can be counted on to flush every year-sometimes twice,although the early flush is from last years growth ,but still... Looks best with some shade from hottest summer sun. Upper 20's have not affected mine.Fertilize in summer. Beautiful slow growing container plant. Very rare to spot one here outside of botanical gardens. That's a shame because they look and do great.

Positive

On Sep 11, 2006, jeri11 from Central, LA (Zone 8b) wrote:

I live in zone 8b and have had this palm for 9 years. It dies back to the ground every year thus I have never had over two years. Everyone thinks it's a sago. But I love it anyway.

Neutral

On Jun 18, 2004, epic1 from Windermere, FL wrote:

Great tree, but a painfully slow germinator. I started 5 (3 survived) in early February (south florida, things start to warm up that time of year). It is now mid june, and all are still developing a crown, with no sign of splitting to allow a leaf. In contrast, I started a c. revoluta in March, and it now bears a single leaf, measuring 6in long by 3in wide. Maybe by next feb I can expect a few leaves.

Positive

On Jan 3, 2004, hactx wrote:

I have two young cycad plants out of a total of 5. They are about 5 months old add about a foot tall.

Positive

On Sep 25, 2003, palmbob from Acton, CA (Zone 8b) wrote:

This is one of the more commonly grown cycads in cultivation, though still relatively rare in the average garden. It is one of the largest cycads, too, getting up to 20'+ in the tropics (Mexico). It has wide, tapering, pointed leaflets which are very smooth and sea-green. It is one of the more frost tender cycads with frosts down to about 28F damaging the foliage. However, the plant will easily survive those temps, and new leaves will come out in the spring.