Plants Beginning with H

Hints:

Temperature: The temperatures aren't set in stone, as most annuals should pop up at any temperatures between 70 and 80 degrees, while some tropicals will prefer the higher end of that range. Perennials and hardy annuals, which tend to like cooler conditions, usually will sprout at any temperatures between 60 and 70 degrees.

Moisture: To keep the seed starting mix moist for your seeds, cover their containers with plastic wrap until the seeds begin to sprout. Use aluminum foil instead for those which prefer darkness for germination.

Chipping or Sanding Seeds: These processes are only ncessary for seeds that have very hard coats, which water won't penetrate. To protect your fingers, hold each seed between the "jaws" of needle-nose pliers on top of a cutting board as you nick it with the tip of a utility knife. To sand the seed instead, rub it against an emery board or sandpaper until you break through the seed coat.

Soaking Seeds: You easily can soak seeds overnight in Styrofoam cups, writing the name of each seed on the side of its cup. If you need to heat the soak-ing water to a certain temperature, use a candy thermometer to measure that temper-ature. Otherwise, use lukewarm (room temperature) water.

Gibberellic Acid: If you need to use gibberellic acid, dissolve a 100 mg packet of the white powder in about 1/2 cup of water overnight. Then add an equal amount of water to the mix to make a 500 ppm solution, which is best for most species, before soaking your seeds in the solution overnight.

Smoke Treatment: For seeds that require smoke treatment, add 1 teaspoon commercial smoke flavoring to every 3 tablespoons of water you are using. For the best results, find a flavoring that contains only smoke and water in its ingredients list.

Cold or Warm Treatment: When seeds need to be kept damp and either warm or cold for a certain number of months, fold a paper towel into a card shape. After writing the name of the seeds and the date on front of the "card" with an indelible marker, soak the paper towel in water, squeeze out the excess water, and place the seeds inside the card.

You can keep several such cards inside a folded-over sandwich bag to help preserve their moisture.

Keep in mind that, when a seed begins to sprout inside the towels, the first thing to emerge usually is a radicle (main root). So, if you pot up the seed at that point, be sure that you position it with the root underground and lower than the seed from which it is protruding.

Plants Beginning with H

Hardenbergia (lilac vine): Sow the seeds 1/8 inch (3 mm) deep in damp and sterile seed-starting mix. Keep the container at 68 degrees (20 degrees Celsius) until the seeds sprout, usually in 20 days or so.

Hedychium (ginger lily): Soak the seeds for 2 hours in hot water and sow them 1/16 inch (1.5 mm) deep in damp and sterile seed-sowing mix. Keep the container at 70 degrees Fahrenheit (21 degrees Celsius) until the seeds sprout, usually in 2 to 6 weeks.

Helianthus (sunflower): Sow the seeds 1/4 inch (6.4 mm) deep in damp and sterile seed-starting mix. Keep the container at 70 degrees Fahrenheit (21 degrees Celsius) until the seeds sprout, usually in about 3 or 4 days.

Heliophilia: Sow the seeds 1/16 inch (1.5 mm) deep in damp and sterile seed-sowing mix. Keep the container at 68 degrees (20 degrees Celsius) until the seeds sprout, often in 3 days.

Heliotropium (heliotrope): Sow the seeds 1/16 inch (1.5 mm) deep in damp and sterile seed-sowing mix. Keep the container at 68 degrees (20 degrees Celsius) until the seeds sprout, often in 5 days, though they can take much longer

Helleborus (Christmas or Lenten rose): The seeds must be fresh to germinate well. If possible, sow seeds outdoors in mid to late summer immediately after they have ripened, covering them with 1/4 inch (6 mm) of soil.

If you must purchase seeds instead, try to get them before the end of the year in which they were harvested. Then immediately place them in a damp paper towel inside a plastic sandwich bag and keep them at 70 degrees Fahrenheit (21 degrees Celsius) for 3 months.

Afterward, move them into your refrigerator for 3 months. The seeds usually will begin to break open a month or so after they have been in the refrigerator or about 120 to 140 days from when they were placed in the paper towels. You then can pot them up in damp and sterile seed-starting mix and keep them in a cool location (preferably not warmer than 50 degrees (10 degrees Celsius) until they sprout.

Hemerocallis (daylily): Sow the seeds 1/8 inch (3 mm) deep in damp and sterile seed-starting mix. Keep the container at 70 degrees Fahrenheit (21 degrees Celsius) until the seeds sprout. Some may spring up within 6 to 8 days, while others can take much longer.

Hermannia: Sow the seeds in damp and sterilized cactus and citrus potting mix, barely covering them with that mix. Keep the container at 73 to 77 degrees Fahrenheit (23 to 25 degrees Celsius) until the seeds sprout in 2 to 3 weeks.

Heuchera (coral bells): Press the seeds into the surface of damp and sterile seed-starting mix, but don’t cover them with the mix. Place their containers under the center of a grow light at 68 degrees (20 degrees Celsius) until the seeds sprout, usually in 9 to 18 days

Hibbertia (guinea flower): Rub the rounded side of each seed againt an emery board until you break through the seed coat and soak the seeds in smoke-infused water for 12 hours. Then sow them 1/16 inch deep in damp and sterilized cactus and citrus potting soil. Keep the container at 75 degrees Fahrenheit (24 degrees Celsius) until the seeds sprout, which often can take 1 to 3 months.

Hibiscus (annual or tropical types with kidney-shaped seeds): Chip and soak overnight any seeds which are large enough for that treatment. For smaller seeds, heat water to 140 degrees, drop the seeds into it, and allow them to sit in the cooling water overnight.

Then sow them 1/16 inch (1.5 mm) deep in damp and sterile seed-sowing mix. Keep the container at 70 degrees Fahrenheit (21 degrees Celsius) until the seeds sprout, usually in 2 or 3 days

Hibiscus (hardy types with spherical seeds): Soak the seeds overnight and sow them 1/16 inch (1.5 mm) deep in damp and sterile seed-sowing mix. Keep the container at 70 degrees Fahrenheit (21 degrees Celsius) until the seeds sprout, usually in 2 to 4 days

Hieracium (hawkweed): Sow the seeds in damp and sterile seed-starting mix, barely covering the seeds with that mix. Keep their container at 68 degrees (20 degrees Celsius) until the seeds sprout, usually in about 5 to 12 days.

Hippeastrum (amaryllis): Float the seeds in a container of lukewarm water kept in a warm location until they begin to make roots, after which they can be potted up.

Houttuynia: In autumn or early winter press the seeds into the surface of damp and sterile seed-sowing mix. Place their container in an outdoor location, such as a coldframe, over winter and the seeds should germinate in 2 or 3 months.

Hydrangea: Press the seeds into the surface of damp and sterile seed-starting mix, but don’t cover them with the mix. Place their container under the center of a grow light at 70 degrees Fahrenheit (21 degrees Celsius) and the seeds should sprout in 20 days or so.

Hylocereus (night-blooming cactus): Press the seeds into the surface of damp and sterilized cactus and citrus potting mix, but don’t cover them with the mix. Place their container under the center of a grow light at 70 degrees Fahrenheit (21 degrees Celsius) and the seeds should sprout in 9 days or so.

Hyoscyamus (henbane): Soak the seeds overnight and sow them 1/8 inch (3 mm) deep in damp and sterile seed-starting mix. Keep the container at 70 degrees Fahrenheit (21 degrees Celsius) until the seeds sprout, usually in 4 days or so.

Hypericum (St. Johnswort): Press the seeds into the surface of damp and sterile seed-starting mix, but don’t cover them with the mix. Place their containers under the center of a grow light at 68 degrees (20 degrees Celsius) until the seeds sprout, usually in 15 days or so.