Favorite Sunflower Seed Collection

Helianthus Germination Information

Helianthus is the botanical name for Sunflower
How to Sow Helianthus:

• Can be sown indoors at 68-86° (will germinate over a wide temperature range)
• Sow 2-3 weeks before planting out
• Expect germination in 5-10 days
• They can be sown outdoors after last frost, but remember: they are a favorite food of birds and rodents and may be eaten by them
• When sowing seed outdoors, we recommend a maximum planting depth of 4X the width of the seed

How to Grow Helianthus:
Transplanting: Transplant when there are at least two sets of true leaves

Spacing: Plant out 2-4 feet apart in full sun in a light soil

Soil: Very tolerant of drought and poor soils

Temperature: Grow on at 70-75° days and 65-68° nights
Additional Care: If planted in partial shade, staking may be necessary to support plants, or plants can be pinched at planting to promote branching

Appearance and Use:

Grown for its edible seeds and for ornamental use in the border. These following flower in late summer and are very large and vigorous. Helianthus annuus, Common Sunflower, grows 4-6 feet tall with daisy-like flower heads in a multitude of sizes and colors, but generally with brown disk flowers and showy yellow ray florets. Helianthus debilis grows 4-7 feet tall and generally have 3 inch, yellow or white flowers. Helianthus giganteus, Giant Sunflower, is a perennial to Zone 3 but is commonly grown as an annual. It grows 9-12 feet tall and sports giant, 1 foot diameter flowers with light yellow to gold showy ray florets. All of the above have large, coarse, hairy, and somewhat sticky leaves

About Helianthus:
Pronunciation:  he-le-an’thus
Lifecycle:  Annual
Origination: Asteraceae, native to North America
Common Name: Sunflower

Superior Germination Through Superior Science

Park Seed offers some of the highest-quality vegetable and flower seeds available in the industry, and there are a number of reasons for this.

First of all, we have humidity- and temperature-controlled storage, and we never treat any of our seeds with chemicals or pesticides. Nor do we ever sell GMO's (genetically modified seeds), so you always know the products you're buying from us are natural as well as safe for you and the environment.

Superior Standards - University Inspected

To make sure we are providing the best seed product possible and that our customers will get the highest number of seedlings from every packet, we conduct our own germination testing and have quality-control measures in every stage of our seed-handling operation. We hold ourselves to standards that are at or above federal and state standards, including testing specific crops more frequently than recommended by federal guidelines. And in order to maintain our organic certification, we welcome Clemson University to inspect us annually to make sure our organic seeds, which are stored and processed separately, are being handled properly.

Hand Packed By Experienced Technicians

Park Seed has been handling and packing vegetable and flower seeds for 145 years, a history that has given us a great understanding of how each variety should be cared for and maintained throughout every step of theprocess, from collection to shipping.

When packing our seeds, the majority are actually done by hand (with extreme care!), and we often over-pack them, so you're receiving more than the stated quantity.

The Park Seed Gold Standard

And many of our seeds are packed in our exclusive Fresh-Pak gold foil packets, which are lined to keep moisture out, so the seeds stay fresher for longer. We carefully pack very tiny or fragile seeds in crush-proof vials to ensure safe delivery to your home. Some of the small seeds are also offered as "pellets" (have a clay coating) to make sowing and growing easier.

When it comes to the kinds of seeds we offer, we are constantly seeking something new and provide many unique and hard-to-find varieties from all around the world. Our on-staff horticulturists are ready and available to share their expertise to help you with the success of these seeds, so you can grow a beautiful and productive garden!

It is important for our customers to know that Park Seed does not sell GMO or treated seed. We do buy a small amount of traditional hybrid seed from Seminis, a division of Monsanto Co., but that is all we purchase from them.

Basically, organic seeds are seeds that are produced without the use and exposure to artificial/chemical fertilizers, insecticides, fungicides, herbicides, and other chemicals. They have to be grown, harvested, stored, and handled under very strict organic rules and procedures. All of our organic seeds are USDA 100% certified organic through Clemson University and the certificate has to be renewed yearly.

Heirloom Seeds are open-pollinated -- they are not hybrids. You can gather and save heirloom seed from year to year and they will grow true to type every year, so they can be passed down through generations. To be considered an heirloom, a variety would have to be at least from the 1940's and 3 generations old (many varieties are much older -- some 100 years or more!).

Hybrid seed are the product of cross-pollination between 2 different parent plants, resulting in a new plant/seed that is different from the parents. Unlike Heirloom seed, hybrid seed need to be re-purchased new every year (and not saved). They usually will not grow true to type if you save them, but will revert to one of the parents they were crossed with and most likely look/taste different in some way.

Extremely small seed such as Petunias and Pentas are shipped as pelleted seed to make them easier to handle and sow. Pelleted seed are coated, usually with clay, to make them larger in size. After sowing, the coating will dissolve when wet and the seed will germinate. Pelleted seeds are shipped in vials placed inside seed packets, which protects them from being crushed. When sowing, be certain to use thoroughly moistened soil, to be sure that the clay coating absorbs enough moisture to dissolve. For sowing pelleted Petunia seeds, place the seeds directly on the soil surface and do not cover with soil, as light aids in the germination.

The ideal temperature to germinate most seeds is approximately 70 degrees F; give or take 1-2 degrees either way. This would be a good germination temperature for most flower and vegetable seeds and would be the most practical and feasible temperatures achieved for gardeners starting seeds in the home. You will notice for some seeds that it is recommended to use alternating day (warmer), night (cooler), temperatures, which is fine if one can provide such conditions. But most people are unable to provide those temperatures in a home setting, so just use the overall 70 degree F recommendation and the seeds should germinate well.

For germination and seedling/plant growth, you want to simulate the natural day-night cycles, and as a general rule, grow lights should be on 8-12 hours per day and off at night. You can vary this timing, as some seeds such as tomato, pepper, petunia, impatiens, and others, benefit from 14-17 hours of light per day (and the remainder of the 24 hour period in darkness). The most common grow lights used are fluorescent; using cool white, warm white, and wide-spectrum fluorescent tubes. These lights work well for germination and for growing plants up to a transplantable size. Fluorescent lights should be kept close though, 3-6 inches above the soil or the growing plants, adjusting the height as the plants grow.

Park Seed stores seed in a special temperature- and humidity-controlled storage facility, which keeps seeds in excellent condition. Our seeds should be good for at least 1-2 years on average. Seed viability and storage time will vary depending on the seed item; some will keep a shorter time and some will keep longer. Seeds should be stored in a cool, dark, dry place. A basement will do (if not too humid), or a cool, dark room or closet. We recommend the best way to extend seed storage life is to store them in something air tight, such as a plastic zipper storage bag or canning jar, and place it in the refrigerator. This will extend the life of seeds for many years.

We recommend the best way to extend seed storage life is to store seeds in something air tight, such as a plastic zipper storage bag or canning jar, and place it in the refrigerator. This will extend the life of seeds for many years.

When sowing seed outdoors, we recommend a maximum planting depth of 4X the width of the seed. When sowing seed indoors, the planting depth can be less, depending on the seed being sown, so it is always best to check specific directions. Here are some general guidelines concerning planting depth in relation to seed size: Tiny, dust-like seeds need to be sown on the surface of the growing medium or soil, uncovered, as they need light to germinate. The planting depth for small seed can be anywhere from barely covering, to 1/8-inch deep, to possibly 1/4-inch deep, depending on the recommendation. Medium seed should be planted at 1/4- to 1/2-inch deep, depending on the recommendation. Larger seeds can be planted 1-inch or deeper, depending on the recommendation.