How to Grow Sunflower Russian Mammoth
Helianthus annuus 'Russian Mammoth'
Your complete guide to growing Sunflower Russian Mammoth.
📷 Wikimedia CommonsWhen to Plant Sunflower Russian Mammoth
Planting windows vary by USDA hardiness zone. Look up yours by ZIP code.
| Zone | Start Indoors | Direct Sow | Harvest |
|---|---|---|---|
| Zone 1 | May – June | July – September | — |
| Zone 2 | April – May | June – August | — |
| Zone 3 | April – May | June – August | — |
| Zone 4 | March – April | June – July | — |
| Zone 5 | March – April | May – July | — |
| Zone 6 | March – April | May – July | — |
| Zone 7 | February – March | April – June | — |
| Zone 8 | February – March | April – June | — |
| Zone 9 | January – February | March – May | — |
| Zone 10 | January | February – April | — |
| Zone 11 | January | January – March | — |
| Zone 12 | January | January – March | — |
| Zone 13 | January | January – March | — |
Companion Plants for Sunflower Russian Mammoth
✓ Good companions
Fixes nitrogen in soil which benefits heavy-feeding sunflowers, appreciates wind protection
Similar growing requirements and complementary root systems, both benefit from deep watering
Benefits from sunflower's tall shade and wind protection while utilizing different soil nutrients
Benefits from afternoon shade provided by tall sunflowers, especially in hot climates
Repels nematodes and aphids while attracting beneficial insects for sunflower pollination
Acts as trap crop for aphids and cucumber beetles that may target sunflowers
Quick-growing crop that breaks up soil around sunflower roots and deters root maggots
Enjoys partial shade from tall sunflowers and helps suppress weeds around sunflower base
✗ Keep away from
Produces juglone which is toxic to sunflowers and inhibits their growth
Allelopathic properties inhibit growth of sunflowers and most other garden plants
May climb sunflower stalks and cause them to bend or break under additional weight
Competes heavily for nutrients and water, both are heavy feeders with similar root zones
