Hey cheesecat yh I've lost one in clay but it was heat stress related, still have another rin clay soil that's doing well and another in a elevated garden bed of sandy loam which is huge now.
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Botany The Acacia Grow Thread
- Thread starter acacian
- Start date
Growing logs with advice and results.
Thanks @_Trip_. A raised garden bed is probably something I should do. Glad you're having success with phleb, it's a unique looking acacia. This is the disease I was talking about, pretty certain it's from excessively wet roots. Acuminata and phleb seem to be quite sensitive comparative to other species.
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I'm no expert but there's a lot of fungal rusts that acacia is susceptible to. Copper sprays and fungicides generally help. But it's also appears more seasonal at least where I am. Phlebs do dry out and drop a lot of phyllodes though. Perfect for extractions.
Beautiful looking phleb and garden!
Sierracacia
Esteemed member
Hey everyone,
Big thanks for sharing your cultivation experience.
I’m starting an outdoor cultivation project growing rare Australian acacias in the Sierra Nevada foothills of California, approximately 60 miles southeast of Sacramento. I want to give complete climate and soil data so any responses are grounded in real conditions rather than native range assumptions.
Location data:
• Elevation: 1,200 ft (366m)
• USDA Zone: 9a
• Soil: Decomposed granite and granitic loam, fast-draining, low organic matter, slightly acidic pH 5.5–6.5. Rocky outcroppings on slopes. Water moves through rapidly even in the wettest months.
• Annual rainfall: 28–33 inches (710–840mm)
• Rainfall pattern: Classic Mediterranean Csa — approximately 95% falls October through April. July and August receive essentially zero precipitation. Bone dry June through September.
Monthly temperature data:
|Month |Avg High |Avg Low |
|---------|-----------|-----------|
|January |55°F / 13°C|39°F / 4°C |
|February |57°F / 14°C|39°F / 4°C |
|March |60°F / 15°C|41°F / 5°C |
|April |66°F / 19°C|43°F / 6°C |
|May |74°F / 23°C|48°F / 9°C |
|June |83°F / 28°C|55°F / 13°C|
|July |91°F / 33°C|59°F / 15°C|
|August |90°F / 32°C|59°F / 15°C|
|September|85°F / 29°C|57°F / 14°C|
|October |73°F / 23°C|51°F / 11°C|
|November |62°F / 17°C|44°F / 7°C |
|December |53°F / 12°C|38°F / 3°C |
Cold floor — the honest numbers:
Average winter lows sit around 38–40°F (3–4°C) and the area rarely drops below freezing — avocado trees are growing and surviving in the town area, which gives a practical indication of the real cold exposure. On radiation frost nights during severe Arctic outflow events, the absolute worst-case temperature on a south-facing slope with good cold air drainage at this location is approximately -7°C (19°F). Events of this severity are rare — roughly once per generation — with the last major event in the region being December 1990. Typical frost nights run -1 to -3°C, approximately 25–40 nights per year, November through February.
Humidity: Low — relative humidity drops to 20–30% in July and August. Winter humidity 60–80% during rain events.
Irrigation: Available year-round from a reliable water source. Drip irrigation planned through the dry season.
Planting site: South-facing granitic slope, not a valley floor. Maximum solar exposure, skeletal fast-draining soil, excellent cold air drainage.
My questions:
1. Acacia acuminata (narrow phyllode variant specifically)
Has anyone grown narrow phyllode acuminata outdoors with 28 inches or more of annual rainfall and had it genuinely establish and thrive — not just survive? My primary concern with this rainfall level is not cold but root rot during the wet winter months — the granitic slope site should provide good drainage but I’d welcome any experience growers have had with fungal root issues in higher rainfall climates and how they managed them. Acacian — how are your acuminatas doing? Are they thriving? What is the lowest temperature they have actually faced and survived? Any other growers with outdoor acuminata in comparable or wetter climates, please share your data — lowest temperatures survived, annual rainfall, and how long the plants have been in the ground.
2. Acacia courtii
My understanding is that courtii is more cold sensitive than acuminata — potentially damaged below around -4°C and at serious risk below -6 or -7°C. Given that my slope site has a realistic worst-case cold floor of around -7°C, courtii sits right at the margin. Is there any grower experience that would clarify whether it could survive a typical winter at this site, even if a severe once-per-generation event might kill it?
3. Acacia phlebophylla
I understand phlebophylla is native to the cool wet alpine environment of Mt Buffalo in Victoria, where summers are moist and mild — the opposite of what I’m offering. My summers are hot and bone dry, with July highs averaging 91°F (33°C) and essentially zero rainfall from June through September. My winters are mild by alpine standards — worst-case -7°C on the slope, with typical frosts only reaching -1 to -3°C.
The question I’d genuinely like this community’s opinion on: does the hot dry Mediterranean summer represent a fundamental barrier for phlebophylla? And does the relatively mild winter — much milder than Mt Buffalo — actually work in its favour compared to the harsher alpine cold it evolved with? Has anyone attempted phlebophylla in any climate with hot dry summers?
Thanks in advance!
Big thanks for sharing your cultivation experience.
I’m starting an outdoor cultivation project growing rare Australian acacias in the Sierra Nevada foothills of California, approximately 60 miles southeast of Sacramento. I want to give complete climate and soil data so any responses are grounded in real conditions rather than native range assumptions.
Location data:
• Elevation: 1,200 ft (366m)
• USDA Zone: 9a
• Soil: Decomposed granite and granitic loam, fast-draining, low organic matter, slightly acidic pH 5.5–6.5. Rocky outcroppings on slopes. Water moves through rapidly even in the wettest months.
• Annual rainfall: 28–33 inches (710–840mm)
• Rainfall pattern: Classic Mediterranean Csa — approximately 95% falls October through April. July and August receive essentially zero precipitation. Bone dry June through September.
Monthly temperature data:
|Month |Avg High |Avg Low |
|---------|-----------|-----------|
|January |55°F / 13°C|39°F / 4°C |
|February |57°F / 14°C|39°F / 4°C |
|March |60°F / 15°C|41°F / 5°C |
|April |66°F / 19°C|43°F / 6°C |
|May |74°F / 23°C|48°F / 9°C |
|June |83°F / 28°C|55°F / 13°C|
|July |91°F / 33°C|59°F / 15°C|
|August |90°F / 32°C|59°F / 15°C|
|September|85°F / 29°C|57°F / 14°C|
|October |73°F / 23°C|51°F / 11°C|
|November |62°F / 17°C|44°F / 7°C |
|December |53°F / 12°C|38°F / 3°C |
Cold floor — the honest numbers:
Average winter lows sit around 38–40°F (3–4°C) and the area rarely drops below freezing — avocado trees are growing and surviving in the town area, which gives a practical indication of the real cold exposure. On radiation frost nights during severe Arctic outflow events, the absolute worst-case temperature on a south-facing slope with good cold air drainage at this location is approximately -7°C (19°F). Events of this severity are rare — roughly once per generation — with the last major event in the region being December 1990. Typical frost nights run -1 to -3°C, approximately 25–40 nights per year, November through February.
Humidity: Low — relative humidity drops to 20–30% in July and August. Winter humidity 60–80% during rain events.
Irrigation: Available year-round from a reliable water source. Drip irrigation planned through the dry season.
Planting site: South-facing granitic slope, not a valley floor. Maximum solar exposure, skeletal fast-draining soil, excellent cold air drainage.
My questions:
1. Acacia acuminata (narrow phyllode variant specifically)
Has anyone grown narrow phyllode acuminata outdoors with 28 inches or more of annual rainfall and had it genuinely establish and thrive — not just survive? My primary concern with this rainfall level is not cold but root rot during the wet winter months — the granitic slope site should provide good drainage but I’d welcome any experience growers have had with fungal root issues in higher rainfall climates and how they managed them. Acacian — how are your acuminatas doing? Are they thriving? What is the lowest temperature they have actually faced and survived? Any other growers with outdoor acuminata in comparable or wetter climates, please share your data — lowest temperatures survived, annual rainfall, and how long the plants have been in the ground.
2. Acacia courtii
My understanding is that courtii is more cold sensitive than acuminata — potentially damaged below around -4°C and at serious risk below -6 or -7°C. Given that my slope site has a realistic worst-case cold floor of around -7°C, courtii sits right at the margin. Is there any grower experience that would clarify whether it could survive a typical winter at this site, even if a severe once-per-generation event might kill it?
3. Acacia phlebophylla
I understand phlebophylla is native to the cool wet alpine environment of Mt Buffalo in Victoria, where summers are moist and mild — the opposite of what I’m offering. My summers are hot and bone dry, with July highs averaging 91°F (33°C) and essentially zero rainfall from June through September. My winters are mild by alpine standards — worst-case -7°C on the slope, with typical frosts only reaching -1 to -3°C.
The question I’d genuinely like this community’s opinion on: does the hot dry Mediterranean summer represent a fundamental barrier for phlebophylla? And does the relatively mild winter — much milder than Mt Buffalo — actually work in its favour compared to the harsher alpine cold it evolved with? Has anyone attempted phlebophylla in any climate with hot dry summers?
Thanks in advance!
Courtiis could survive but they are fussy in the cold I have a min for short periods of -4c and average night temps of 1c for 4 months a year and have several courtiis growing, I have found they don't like sandy loam as much as acuminata they seem to respond to more moist soil with slightly better fertilizer. Your climate sounds good for acuminata. And Mt buffalo hits 37c and it gets hot and dry in summer. They're all quite drought hardy but will need water in the warmer months especially when being established. Phlebophylla I would say is harder to grow.
My best phleb is in very well draining poor quality soil in a raised garden bed. Biggest I've seen outside of its native environment and much healthier than the ones in the wild.
Acacian will have more information to add.
Ps we have 45c summers. I'm not too far from Mt Buffalo but much similar altitude to you. I think you'll have a good chance.
My best phleb is in very well draining poor quality soil in a raised garden bed. Biggest I've seen outside of its native environment and much healthier than the ones in the wild.
Acacian will have more information to add.
Ps we have 45c summers. I'm not too far from Mt Buffalo but much similar altitude to you. I think you'll have a good chance.
I’m in PNW and growing a floribunda strain atm entirely outside all winter in an unheated greenhouse. In summer they are in the yard. They are only a year old now . It’s PNW lol so ya I do not want them being rained on for 7 months.
In the past I grew the narrow phyllode variety of acuminata. I never tried it outdoors all winter back then but I bet it would be okay and I’m starting some this week.
In the past I grew the narrow phyllode variety of acuminata. I never tried it outdoors all winter back then but I bet it would be okay and I’m starting some this week.
Sierracacia
Esteemed member
Thanks _Trip_. That is some very helpful information. It sounds like i have a good chance with acuminata and phlebophylla. What is the annual rainfall in your area? My biggest concern at this point is fungal issues or root rot. I plan to plant on a super well draining granitic slope or ridge though so that might make it work well.
Sierracacia
Esteemed member
Thanks Jamie01. Very encouraging.
I plan to plant some floribunda as well but need to find a way to source seed for an active variety.
What is the coldest temp your acuminata and floribunda ever survived outdoors?
Similar to you approx 750mm so like almost 30inches anually.
Just note they prefer well draining soil. But I have 2 broad phyllode acuminats that have survived poor clay soil and 2 years of quite serious flooding.
However I must say our native fungi and bacteria is likely quite different, however acacias are tough and adapatable.
It doesn’t get all that cold here. I’m on an island and I think all winter this year we had like a cm of snow that stuck around a few hours. We had a few nights around -5C etc but it warms up in the day. We get that one cold snap a year for a week usually then it’s back to 3 seasons.
Sierracacia
Esteemed member
Sounds like our conditions are quite similar. This is the crucial information that i needed. Really appreciate the data your sharing from all your direct experience and research.
Sierracacia
Esteemed member
Sounds like a special location. Are you in the rainshadow? How many millimetres of rain do you get annually?
1481 mm a year we average.
