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Zone 9 Seed Starting: When To Start Seeds In Zone 9 Gardens

Zone 9 Seed Starting: When To Start Seeds In Zone 9 Gardens


By: Mary H. Dyer, Credentialed Garden Writer

The growing season is long and temperatures tend to be mild in zone 9. Hard freezes are uncommon and planting seeds is a breeze. However, in spite of all the benefits associated with mild-climate gardening, selecting an optimal schedule for starting seeds in warm climates will ensure the best possible outcome. Read on to learn more about starting seeds in zone 9.

Seed Starting Guide for Zone 9

The last frost date for zone 9 is generally in early February. While USDA growing zones and estimated frost dates are helpful for gardeners, they are merely guidelines based on averages. Gardeners know that when it comes to weather, there are no guarantees.

With that in mind, here are a few tips on zone 9 seed planting and when to start seeds in zone 9:

The best source of information on seed starting is on the back of the seed packet. Make note of the suggested germination times, then create your own schedule by counting backwards from the first average start date in early February. While the information tends to be general, it can still help you determine when to start seeds in zone 9.

Remember that gardening is not an exact science, with many questions and no perfect answers. Many plants perform best when planted directly in the garden such as:

  • Spinach
  • Peas
  • Carrots
  • Sweet peas
  • Cosmos
  • Forget-me-nots

Others such as tomatoes, peppers, and many perennials do best with a head start in a warm, well-lit environment. Some seed packets will provide helpful tips; otherwise, it’s up to you to figure it out.

Once you’ve counted backwards from the last expected frost date, you may need to tweak the schedule a bit. For example, if you’re starting seeds indoors in a cool room, consider getting started several days earlier. If the room is warm or you’re growing in a greenhouse, hold off a week or two to prevent plants from becoming too big, too fast.

Planting seeds is always an adventure, regardless of the weather. However, starting seeds in warm climates presents possibilities that gardeners in more northern climates would envy. Take your best shot, be willing to experiment, and chances are good that you’ll be delighted with the results.

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Read more about Zone 9, 10 & 11


Seed Germination Guide

This article was published originally on 1/13/2017

While gardeners can purchase bedding plants at garden centers and greenhouses in spring, many gardeners prefer to get a head start on the garden season by starting flower and vegetable seedlings indoors. Growing quality seedlings indoors requires high quality seeds, a well-drained growing medium, containers, proper temperature and moisture conditions, and adequate light.

Germination requirements (light and temperature) vary among the different annuals and vegetables. The various crops also differ in the length of time from seed sowing until the seedlings are planted outdoors.

The following chart provides germination and growing information for commonly grown annual flowers and vegetables.



Light (1)
Germination
Temperature (2)
Growing
Temperature (2)
Crop
Time (3)
Annuals
Snapdragon L 70-75 60-65 8-10
Wax Begonia L 70-75 60-65 10-12
Periwinkle (Vinca) C 75-80 70-75 8-10
Celosia C 75-80 70-75 7-9
New Guinea Impatiens LC 75-80 70-75 8-10
Geranium C 70-75 65-70 10-12
Petunia L 75-80 65-70 8-10
Scarlet Sage (Salvia) L 75-80 70-75 8
Coleus L 70-75 65-70 8-10
Marigold C 70-75 65-70 6-8
Pansy LC 65-70 60-65 8-10
Zinnia C 70-75 65-70 4-6
Vegetables
Onion LC 70-75 65-70 8-10
Dill L 65-70 65-70 5-6
Kale C 65-70 60-65 4-6
Cauliflower C 65-70 60-65 4-6
Cabbage C 65-70 60-65 4-6
Broccoli C 65-70 60-65 4-6
Pepper C 70-75 65-70 6-8
Watermelon C 75-80 70-75 3-4
Muskmelon C 75-80 70-75 3-4
Cucumber C 75-80 70-75 3-4
Squash and Pumpkin C 75-80 70-75 3-4
Tomato C 70-75 65-70 5-7
Basil C 65-70 60-65 5-6
Parsley C 70-75 65-70 6-8
Eggplant C 70-75 65-70 6-8


(1) Light conditions during germination are critical for many annuals and vegetables. The seeds of some plant species require light for germination. (In the table above, seeds that require light for germination are designated with the letter L in the Light column.) After sowing these seeds, lightly press them into the germination medium, but do not cover them. The seeds of other flowers and vegetables require darkness (C) and should be covered with the germination medium. Finally, those designated LC should be lightly covered, leaving the seeds as close to the soil surface as possible.

(2) Temperatures are in degrees Fahrenheit. The listed temperatures in the Growing Temperature column are daytime temperatures. Night temperatures should be a few degrees cooler.

(3) Crop time is the number of weeks from the sowing of seeds to planting outdoors.


How to Grow Rhodochiton From Seed

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Rhodochiton, also known as the purple bell vine, is a twining perennial that yields dark purple blossoms that will add a splash of color to your garden throughout the summer and fall months. Rhodochiton yields showy blooms that enhance the beauty of a backyard garden or add flair to a container garden or hanging basket. The plant grows well in Zones 9 and 10.

Fill a seed-starting tray with potting soil.

Sprinkle rhodochiton seeds over the soil, spreading them evenly among each of the sections. Gently press the seeds into the soil.

Fill a spray bottle with warm water and mist the soil until it is moist.

Cover the seed-starting tray with plastic wrap and place it in a warm and sunny spot indoors. The seeds should get at least 8 hours of sunlight each day to encourage them to sprout.

Take the plastic wrap off the tray once the seeds germinate, which can take between 14 and 45 days.

Water the seeds two or three times each week until the overnight temperature begins to stay consistently above 32 degrees Fahrenheit.

Transplant each sprout into 4-inch pots. Fill a pot with potting soil and make a small hole using a spoon. Carefully place a sprout into the hole and cover with potting soil. Water well.

Poke a trellis into the soil toward the back of the pot to encourage the rhodochiton to twine upward.

Place the pot in a sunny spot on your porch or patio. The plants need full sun to thrive.

Water your rhodochiton regularly to keep the soil moist so the roots can establish themselves.


Seed starting for Beginners Part 1

Its that time! It is the time of year – time to appease our need for the smell of soil and the love of nurturing green life. Many people spend a fortune in plants at the box stores and green houses. Good for them, there is nothing wrong with that. However, paying $2-3 per cabbage plant makes me wonder why they don’t just buy cabbage at the grocery store. Not only is it expensive, but missing the seed starting is missing one of the best parts! Watching and nurturing the beginnings of life is so enjoyable. I have outlined a very simple and short seed starting plan below. For a much more in depth overview of seed starting and one of my favorite reference manual, please see, The New Seed Starters Handbook by Nancy Bubel.

There are many seed companies that have wonderful products. When you are buying seeds, look for companies that specialize in northern growing conditions or has a full array of seeds for every growing condition. Much of what will grow in the lower 48 may not do well here in Alaska. This is most often due to our extreme amount of daylight, cold soils, and cold water. Too much daylight is not always good and can really confuse the plants native to a different latitude. Plants determine when to do much of their reproduction and dormancy by way of daylight, not temperature. Territorial Seed Company, Johnnys Select Seeds, Denali Seed Company, Foundroot, Fedco Seeds and many more are wonderful companies to use. Territorial Seed Company is a Pacific Northwest company and has some, hard to find varieties, as well as a catalog that is food for the soul around the depths of January’s darkness. Johnny’s Select Seeds has almost everything a person could imagine as well as some amazing tools that are designed and used by Elliot Coleman for year round northern gardening. Denali Seed and Foundroot are both seed companies that specialize in Alaskan growing conditions. Fedco is a company in Maine that has some very cold hardy products at a very good price. Enjoy the vast array of catalogs that these companies send in January. Sort through them with your feet up by the fire, steaming cup of tea next to you, and the snow piling up outside. While your dreaming of sunny days and every variety of squash or strawberry, remember that it is easy to go overboard! Each one of those little seeds will need to be planted, hardened off, transplanted, weeded, watered, harvested, preserved, and composted!

Supplies: These supplies are essential for seed starting. They are widely available, but I’ve included some links to where you can purchase them as well. The links are highlighted in blue and simply click on them to bring up an example item. For a simple setup, you will need the following:

  • seed starting soil
  • small plastic containers with good drainage
  • seeds
  • water
  • fluorescent light or a very sunny south facing window
  • permanent marker/plastic for labels
  • fan

Optional items are all very helpful and worthy of the investment but not required and include the following:

  • heat mat
  • bakers rack
  • welded wire fencing around your setup to guard against cats, dogs, and kids
  • trays without holes
  • plastic domes
  • outlet power strips
  • timers
Simple seed starting setup
  1. When: When to start the seeds is a surprisingly complicated answer. Some people simply look at all their seed packet and count backwards from their last frost date. Others consider the type of plant they are planting and note if it is a plant that can handle some mild frost so that they can push the timeline a little and get their plants out early. Plants in the brassica family (cabbage, kale, broccoli, etc…) are very frost resistant. Some plants take a long time and need to be started in January/February such as onions, celery, thyme, rosemary, and parsley. Most garden plants are started around April in South central Alaska. Keep in mind that those tiny little seeds will require some serious room once they are really going strong. My first year growing pumpkins was a very awkward year of balancing a shocking amount of greenery in my dining room. Bakers rack getting ready to fill for planting Soil is too dry Soil is perfectly moist and holds it shape after I let my hand relax Place your small containers in a leak proof tray for gentle watering from below. Place two seeds in every pot unless a “special” case These plastic domes help hold in moisture and increase germination.

    Heat mats: Heat mats are worth the small investment, however, they are not necessary. They speed and increase germination rate by a very large amount. You can purchase an inexpensive heat mat from Alaska Mill and Feed. Later, when you know exactly how you are going to arrange your seed starting station(s), buy the more precise mats from Johnny’s. First time seed starters need not worry too much about specific temperature control for the heat mats. If you are doing seed starting on a larger scale, I like to use temperature monitors. They make sure the mats are not getting too hot. It is rare for that to happen but it will occasionally occur.

    Heat mat temperature monitor Seedling Emergence: As soon as the seedlings start coming come up, remove their heat mat and plastic cover. These little seedlings are just starting to emerge. Time to put them under the light.

    Place them directly under a fluorescent light and at room temperature. Seedlings like it light, not too hot, and with a soft breeze. More information on how to care for seedlings coming soon in part two of seed starting for beginners!


When it comes to starting seeds, terminology can often be confusing. The terms “hardy annuals” and “half-hardy annuals” often confound those of us who garden in the Northeast. We’ll see the terms used in seed catalogs and books, but more often than not, few gardeners in North America can name examples of one or the other.

The terminology works if you live in a climate where winters are mild, such as the Pacific Northwest or California, but for Northeasterners, who often experience brutal, cold winters, it makes more sense to think of annuals in two different ways. There are hardy annuals (cool-growing ones) and tender annuals (warm-loving ones), and within these groups, some must be started early, and some only perform well if direct-sown outdoors. But as with any set of rules, some are meant to be broken.

Pansies should be started indoors so that they can be ready to go outside in early spring. Photo: Matt Mattus

Certain cool-growing annuals perform best when started indoors …

Cool-growing hardy annuals include some common flowers such as pansies (Viola × wittrockiana cvs.), annual dianthus (Dianthus spp. and cvs.), stock (Matthiola incana and cvs., Zones 5–10), and sweet peas (Lathyrus odoratus). In mid-February to early March, these flowers must be started early indoors if one has a bright, cool growing area, preferably under grow lights. All of these flowers grow best in cool conditions (50° to 60°F) and should be hardened off early outdoors just as maple trees (Acer spp. and cvs., Zones 3–9) start blooming.

Despite their warm-sounding name, these gorgeous desert bluebells do well germinating in the cold outdoors of an early Northeast spring. Photo: Matt Mattus

… and some perform better when direct-sown outdoors

Many hardy annuals are sensitive if not intolerant of any root disturbance, which adds an element of difficulty to their culture—especially if they want to germinate in the cold outdoors and if they dislike hot weather. This group includes clarkia (Clarkia amoena), desert bluebells (Phacelia campanularia), corn poppies (Papaver rhoeas), love-in-a-mist (Nigella damascena), giant larkspur (Consolida ajacis) and Queen Anne’s lace (Ammi majus). For those who garden in warmer climates, these often just require a sowing outdoors in the fall, but in the Northeast, we need to be more creative.

Direct-sowing frequently intimidates gardeners, but it’s worth doing if one wants tall, healthy giant larkspurs or drifts of corn poppies, and it can work just fine if your area of the Northeast is experiencing a mild winter. If you can work your soil in late February or early March, all of the hardy annuals in the above paragraph can be direct-sown outdoors. Be patient, for most will germinate late. Corn poppies will not germinate until they’ve experienced a few days near 70°F, and most germinate best at 80°F, so it takes time. Examine their bed carefully, and learn how to distinguish weeds from young plants. It may require a magnifying glass.

These foxgloves are growing in plug trays due to their sensitive roots. Photo: Matt Mattus

It’s possible to start some traditionally direct-sown cool-loving annuals indoors

While many of the above group of annuals are best suited to being direct-sown outdoors, some can be started indoors in February. The trick is to keep the growing area cool (50° to 60°F) and to sow seeds thinly if not individually. Sow one or two seeds per cell in plug trays, then remove all but the strongest ones.

The root-sensitive direct-sown annuals also respond well to being started in plug trays (trays of small growing cells often called 72’s or 244’s). This is the method used by most flower farmers who need hundreds of Queen Anne’s lace plants or annual foxgloves (Digitalis spp. and cvs.) in densely planted rows.

Zinnias grow quickly in warm weather and will shoot up like weeds if sown outdoors in early to late summer. These ‘Persian Carpet’ zinnias were sown in August and still had ample time to bloom. Photo: Matt Mattus

Many tender, half-hardy annuals do best direct-sown outdoors late in the season …

As for the “warm-loving” or “half-hardy annuals,” here’s a tip: Don’t start them too early indoors. If you find that your cosmos (Cosmos bipinnatus) aren’t as tall as you remember, or if your double zinnias (Zinnia elegans) have all turned dingy and single by midsummer, this may be because you sowed seeds too early. Hold off sowing until June 1 or later, and then sow seeds outside.

Just scratch a row in a raised bed near your lettuce or radishes, and then transplant these rapidly growing annuals into your flower bed. Zinnias started in early summer outdoors will far outperform any started in earlier in spring.

If you’ve struggled with sunflowers (Helianthus annuus), for example, keep in mind that they abhor being transplanted. Sow them in mid-June out in the garden, when the soil is warm and summer is well underway. Thin out all but one per square foot, and stand back. The tallest sunflowers come from these late-sown and never-touched-by-human-hands seedlings. Other warm growers that are grow quickly and are best sown outdoors are zinnias, cosmos, spider flowers (Cleome spp. and cvs.), China asters (Callistephus chinensis), and nasturtiums (Tropaeolum spp. and cvs.).

Globe amaranths and other annuals in the amaranth family take a little longer to grow even though they are heat-loving. Give them a head start by seeding them indoors. Photo: Brittany Carlson

… but there are some tender, half-hardy annuals that perform better when started indoors

Some warm-weather annuals need extra time and benefit from a head start indoors. For cockscomb (Celosia spp. and cvs.) and globe amaranths (Gomphrena globosa), you should pluck out all but one seedling, as they dislike root disturbance at any size. Cockscomb, globe amaranth, and flowering tobacco (Nicotiana sylvestris) should all be started indoors and can be covered lightly while germinating. Floss flower (Ageratum houstonianum) should be started indoors too, but do not cover the seed, as it needs lots of light to germinate.

There is a lot of information out there to guide you through the processes of direct-sowing and starting seeds indoors. For example, see All About Seed Starting. I’ll leave you with this: If you do want to buy grown annual plants at the garden center this year, save your money for those annuals that needed a longer time in a greenhouse, such as snapdragons (Antirrhinum majus, Zones 7–11) and petunias (Petunia spp. and cvs.).

Note: All plants mentioned in this article are annuals unless indicated otherwise with USDA Hardiness Zone ranges.

—Matt Mattus is a lifelong gardener and vice president of the Worcester County (Mass.) Horticultural Society. He’s written two books: Mastering the Art of Flower Gardening and Mastering the Art of Vegetable Gardening.

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