Sunflower, Mammoth Russian
Huge heads are ideal for competition at fairs.
Beds, Borders, Cut Flowers
Sunflowers are grown from seed sown directly in the garden after frost.
- Direct sow seeds in average soil in full sun after all danger of frost.
- When choosing a site consider that sunflowers need a well-drained soil. They face the sun, so make sure they are in an open area of the garden. The taller varieties will cast shadows on other plants, so plant these at the north end of your garden.
- Prepare the soil by removing weeds and working organic matter into the top 6-8 inches of soil; then level and smooth.
- Most plants respond well to soils amended with organic matter. Compost is a wonderful form of organic matter with a good balance of nutrients and an ideal pH level, it can be added to your planting area at any time. If compost is not available, top dress the soil after planting with 1-2 inches of organic mulch, which will begin to breakdown into compost. After the growing season, a soil test will indicate what soil amendments are needed for the following season.
- Sow seeds ½ inch deep in groups of 2 or 3 seeds. Space the groups 18-24 inches feet apart, depending on the variety.
- Firm soil lightly, water and keep evenly moist.
- Seedlings will emerge in 7-10 days.
- Thin to one plant per group when seedlings have two sets of leaves.
- Keep weeds under control during the growing season. Weeds compete with plants for water, space and nutrients, so control them by either cultivating often or use a mulch to prevent their seeds from germinating.
- Mulches also help retain soil moisture and maintain even soil temperatures. For annuals an organic mulch of shredded leaves lends a natural look to the bed and will improve the soil as it breaks down in time. Always keep mulches off a plant’s stems to prevent possible rot.
- Keep soil evenly moist but not wet.
- Once established sunflowers can tolerate drought.
- No fertilizer is needed unless the soil is poor. Do not over fertilize.
- Monitor for pests and diseases. Check with your local Cooperative Extension Service for pest controls recommended for your area.
- Some varieties only produce one bloom so once the bloom is spent, the plant may be removed.
- Remove plants after they are killed by frost in fall to avoid disease issues the following year.
- Edible sunflowers will mature in about 3 months or more after sowing. To harvest the seeds, cut the heads off after the stalks are quite dry but before fall or winter rains come. Check the flower heads for maturity to see if the florets in the center of the flower disk have shriveled and the back of the flower head is turning yellow, or the head is starting to droop. Cut flower-heads with a foot of the stalk attached. Hang heads in a warm, dry, well-ventilated place so the seeds may fully ripen and dry. Cheesecloth, netting or a paper bag with holes punched in for ventilation should be placed over the head to protect the seeds and to collect those that may drop from drying.
- Shorter varieties may be grown in containers. Be sure to use a commercial potting mix.
- Pollenless varieties make terrific cut flowers.
SunFull SunHeight9-12 feetSpread36-40 inchesOrnamental UseBeds, Borders, Cut FlowersLife CycleAnnualSow MethodDirect SowFloweringtrueBloom Duration5
Sunflower, Mammoth Russian is rated out of 5 by 14.Rated 5 out of 5 by bedhr from Headturner Grew these in a circle where a tree had died and they filled in the spot and were wonderfully tall and fun!Date published: 2016-02-09Rated 5 out of 5 by Desi from Rabbit food All the reviews are right, but watch out for RABBITS!! They love these plants.Date published: 2010-06-18Rated 5 out of 5 by waycross48 from QUICK STARTERS!! I planted these for my grandchildren and although the package says "7-10" days, ours sprouted to about 2 inches in just 3 days!! They were thrilled. The plants are now about 6-7in tall in about a week's time. These are great plants for a younger child's first gardening experience. They sprout almost overnight and grow so very quickly that the children are constantly excited by their development. I highly recommend this variety of sunflower and we can't wait to see the giant seed-filled flowers. I will revise my review when we actually get flowers. But, for now, we are all very thrilled with the results. These appear to be very strong, healthy, plants with large bright green leaves and thick healthy stems.Date published: 2010-04-25Rated 5 out of 5 by Leavened from more than I expected My grandson and I planted some of these last season. Several grew to over 9 feet tall. the seed blossom was over a foot in diameter. I'm going to plant again this year.Date published: 2010-01-15Rated 5 out of 5 by BKBK from What a giant My mammoth's grew to 12 feet tall. Out of a dozen un-staked plants, only one was damaged by the wind. Easy and quick to grow!Date published: 2009-06-04Rated 5 out of 5 by tuxedocat from sunflower mammoth Although I did purchase sunflower mammoth seeds that are labeled Burpee, This is the first time I ever planted sunflowers. The thrill of it was fantastic and very gratifying. The plant got approx. 11foot tall. But, because we have had a lot of 90 degree/humid days here, the sunflower head has been drooping and the surrounding yellow leaves are dying off. I thought maybe it was the temps but, maybe it could just be a disease or some kind of wilt.Date published: 2008-08-10Rated 5 out of 5 by mjk08 from Mammoth Sunflower Easy, to grow. I planted twelve sunflowers for the first time ever and did not realize that these are Mammoths and should be planted two feet apart in order to ensure good growth, so I had to relocated about five of these sunflowers plants (when they were about 3ft tall) to another area in my garden (the replanted ones are not pictured though), and I am happy to say they all survived and are also growing very big. As for my main sunflower garden one the plants (third from the left) is sprouting about 10 blubs, all over all I still can't believe I got all this from seeds!Date published: 2008-08-09Rated 5 out of 5 by wilbar from great grower i planted mid may and the largest of the bunch is 5'tall july 20. almost every seed germinated,they transplanted well,and are growing like crazy, even in the sand and southern red clay. I planted them all around my vegetables and flowers,being careful not to block their sunlight,and they have made the most lush backdrop for my landscape that already adds so much depth to my displays,and they haven't even bloomed yet. I am very anxious to see how many mature to bloom.Date published: 2007-07-20