Starting Seeds Indoors: A Zone by Zone Guide (2024)

Embark on your gardening journey with confidence by mastering the art of starting seeds indoors. This essential practice lays the groundwork for a successful growing season, allowing you to cultivate a diverse array of plants from the comfort of your home. To ensure gardening success, it's essential to have the right tools and supplies on hand. From seed trays and potting mix to grow lights and heat mats, these essentials provide the optimal environment for seed germination and early seedling growth. With proper care and attention, you'll soon be rewarded with robust and healthy plants ready for transplanting into your outdoor garden. Delve into the world of starting seeds indoors and set yourself up for gardening triumph with this guide for starting seeds indoors in Colorado.

Starting Seeds Indoors: A Zone by Zone Guide (1)

Starting Seeds Indoors: Essentials for Gardening Success

Gardening in Colorado comes with a plethora of challenges one must learn to overcome. From our unpredictable weather and fluctuating temperatures to our short growing season and arid climate, starting your garden plants from seed indoors is essential if you want to have a thriving and productive garden.

The Growing Season

As we just mentioned, our growing season in Northern Colorado is short. It is generally safe to start planting after the average last frost date, which is often marked by Mother’s Day or sometime around the middle of May. While the weather is generally warm enough, this date is an average and there still is a slight chance of frost. (Pro tip: It is always recommended to keep some frost cloth handy just in case freezing temperatures roll in unexpectedly.) The first average frost date for Northern Colorado is generally around the end of September/beginning of October. So, this gives Colorado gardeners just around four months of quality growing weather. For some plants with longer maturity dates, however, this is not quite enough time. By the time they start to produce a steady stream of produce, the season will be nearly at its end. This is where the practice of seed starting comes into play. Seed starting indoors allows those plants with longer days to maturity to get a head start on the season, ensuring that you will get a full season of produce from them.

Tools and Supplies for Seed Starting Indoors

Having the right tools and supplies for seed starting is imperative. It is important to use seed starting mix or pellets specifically made for seed starting. You will also want trays with clear plastic covers to help keep in moisture and create an environment similar to that of a greenhouse. Keeping your seedlings warm is also so important. Seedling heat mats keep your growing environment at the perfect temperature to help encourage germination and the growth of your plants. As your plants grow, you will also eventually have to increase the pot size. Peat pots are

Starting Seeds Indoors: A Zone by Zone Guide (2)

great for this, as they are biodegradable and make upsizing, as well as transplanting into your garden, a breeze. Other tools such as misters and grow lights can also make a huge difference in your seed starting endeavors. Here is a list of recommended seed starting tools and supplies:

The Benefits of Starting Seeds Indoors

Give Your Plants a Head Start

Starting your garden plants from seed indoors means that by the time the weather has warmed up enough to plant things outdoors, your garden fruits and veggies will already have had 6-8 weeks to grow, giving them a jump on the growing season, meaning that you get more produce quicker and for longer.

More Options for What You Can Grow

Another benefit to starting your crop from seed is that there are so many more options for what types of fruits and vegetables you can grow. Buying plant starts from your local garden center is an easier alternative for some, but this limits you to growing only what plants are in stock. Plus seed packets are a fraction of the cost and provide you with seeds to last multiple growing seasons.

Seed Starting is Less Expensive

As we just mentioned, the alternative to seed starting indoors is purchasing plant starts from your local garden center. However, due to the time, energy, and resources put into growing plant starts, they tend to be significantly more expensive than seed packets.

Greater Sense of Achievement

Growing all of your garden plants from seed, while not an extremely difficult task, creates a massive sense of achievement. There is nothing quite like looking out over your garden mid-season and seeing everything you fostered from seedlings into the beautiful and productive plants they are today.

How to Start Seeds Indoors in My Zone?

If this is a question you have come across, the answer is simple. If you are starting your seeds indoors, the hardiness zoneyou are in does not matter, because it is indoors. Hardiness zones only affect plants when planted outdoors, so the only time you would need to take into consideration the planting zone you are in is when moving your plants from inside your home to out in your garden. The first and last average frost dates will vary from zone to zone, and certain plants may grow better in some zones and not in others. The state of Colorado consists of zones anywhere from 3b to 7b depending on if you are high up in the mountains or down in the desert, though the majority of the state sits mostly in the USDA plant zone 5 and 6. So, regardless of what zone you find yourself in, the process of starting garden plants from seed indoors will be the same. What will be different is what types of plants will thrive in your climate and when it is safe to move them outside. Be sure to do your research based on what USDA hardiness zone you live in, or visit your local garden center and nurseryfor information on your zone and what you should plant.

If you are looking for a step-by-step guide on how to start your seeds indoors, check out our blog, "Seed Starting Basics: The Importance of Starting Seeds Indoors in Colorado", to find all the information you need to start your seeds from scratch and get ahead of your spring gardening.

Which Vegetables Take the Longest to Grow from Seed?

Starting Seeds Indoors: A Zone by Zone Guide (3)

Several vegetables have longer days to maturity, meaning they take a longer time to grow and produce harvestable crops. These vegetables require patience and careful planning, but the delicious and nutritious harvest they provide is well worth the wait. Some of the vegetables with the longest days to maturity include:

Tomatoes

Most varieties of tomato seeds require around 80 days to reach maturity and start producing fruit. Generally the larger the variety the longer the days till maturity.

Winter Squash

Varieties like butternut squash, Hubbard squash, and spaghetti squash can take anywhere from 80 to 120 days to mature, depending on the variety and growing conditions.

Pumpkins

Pumpkin seeds typically require around 90 to 120 days to reach maturity, with larger varieties often taking longer to grow.

Peppers

Most pepper plant seeds also take somewhere around 80 days to reach maturity. Many varieties can be harvested early, however flavor and nutritional value will be higher if they are allowed to ripen fully.

Brussels Sprouts

Brussels sprouts are slow-growing vegetables that can take around 90 to 110 days to mature. They are often grown as a fall crop, as cooler temperatures improve their flavor.

Artichokes

Globe artichokes are vegetables that can take up to 150 days or more to reach maturity from seed. They require a long growing season and may not produce harvestable buds until the second year of growth.

Leeks

Leeks have a long growing season and can take anywhere from 90 to 120 days or more to reach maturity. They are often planted in early spring for a fall harvest.

Rutabagas

Rutabagas are root vegetables similar to turnips and can take around 90 to 120 days to mature. They are often planted in late spring for a fall harvest.

Garlic

Garlic is another garden plant that has a rather long maturity period, taking anywhere from 120-150 days to reach maturity. This garden plant is usually planted 4-6 weeks before the average last frost and is generally ready to harvest by the end of the growing season.

Potatoes

While easy to grow, potatoes can take a while to reach maturity, averaging around 80-100 days depending on the variety. Plant your potatoes early in the spring for a fall harvest.

Eggplant

When started from seed, eggplant can also take anywhere from 100-120 days to reach maturity. Due to this long maturity period, it is ideal to start this garden plant from seed indoors 6-8 weeks before the start of the growing season.

Set Yourself Up for Success with Seeds from Bath Garden Center

At Bath Garden Center & Nursery, we are here to help with all your gardening needs! From seeds and supplies to gardening tools, plant material, and more, our Garden Center is truly your one-stop shop for all of your growing endeavors. If you have questions or need help, feel free to visit us in-store. You can also give us a call or fill out a contact form. We look forward to assisting you!

Starting Seeds Indoors: A Zone by Zone Guide (2024)

FAQs

When should I start seeds indoors for my zone? ›

Those who live in hot climates—Zones 8 or 9, for example—may be able start seeds as early as December. Northern gardeners, like those who grow in Zones 3 or 4, should wait until March or April to start most seeds, depending on the plant's germination period. Don't fret if you have to wait a little longer.

How many seeds per hole when starting seeds indoors? ›

Like most things in gardening, there are always exceptions to this rule of 2-3 seeds per hole. If you're planting large seeds like cucumbers, melons, or pumpkins, you should only use one seed per hole. However, you can still plant seeds close together and then thin them out once they've established themselves.

What is the easiest way to start seeds indoors? ›

A seed starting tray is the easiest way to start seeds indoors for beginners and expert gardeners. These cells are ideal since they are usually made of a porous material that allows for water absorption and roots, when big enough, to grow right through the walls.

What is the best soil for starting seeds indoors? ›

Commercial seed-starting mixes, usually composed of vermiculite and peat, without any true soil, are recommended for starting seeds. They're sterile, lightweight and free from weed seeds, with a texture and porosity especially suited to the needs of germinating seeds and tiny seedlings.

What happens if you start seeds indoors too early? ›

But, starting your seeds too soon is still a problem. How? Seeds sown too early will result in bigger plants which then need to be potted up into bigger containers which quickly take over your seed starting area/house and cost you more money is potting soil, organic fertilizer and pots.

When to start seeds indoors zone 7? ›

Zone 7 has a medium length growing season. In general, it lasts from April to November. If you live in zone 7, we recommend starting seeds indoors before the first frost date.

Do I plant the whole packet of seeds? ›

If only a few plants are needed, it is not necessary to plant all the seeds in a packet.

Should you water seeds right after planting? ›

Using a small plastic tub or tray, add in your soilless mix. Then pour in just enough water to saturate it to “wrung-out sponge” wetness. The idea here is that the soil is already moist when you plant your seeds, so you don't have to worry about watering for a few days.

How often do you water starting seeds indoors? ›

Most seedlings require water every day or every other day. First, check the soil moisture using your finger by checking the soil color near the drainage hole. If the soil feels or appears dry or brittle, irrigate thoroughly until water pours out of the bottom of the tray, then stop.

What is the cheapest way to start seeds indoors? ›

It's very possible to create an affordable seed starting setup without fancy equipment! You can successfully sprout seeds in things like egg cartons and yogurt cups. Soil for seed starting can be collected from your garden and baked so that it's sterile, and you can use inexpensive shop lights as grow lights.

Can you use egg cartons to start seeds? ›

You can use egg cartons as a seed-starting tray! Depending on the type of carton you have, you can even cut apart the individual sections and plant them, as the carton will biodegrade. Be sure to poke small holes for drainage, and put the cartons on a tray or in a shallow pan to catch any residual water.

Should you soak seeds before planting indoors? ›

If you're storing and sowing seeds inside, they won't go through a cold winter, which some need to signify it's time to wake up and grow. To ensure high germination rates, wake seeds up, and potentially speed up the process, soak seeds before sowing them to soften and loosen that outer protective layer.

Can I use potting soil for seed starting? ›

Although potting soils may be used to start seeds, they tend to have a more coarse texture and may contain field soil, compost or composted manure along with vermiculite, peat moss or perlite. Some seed-starting or potting mixes may contain fertilizer as an additive.

How long can seedlings stay in egg cartons? ›

But you also can't leave your seedlings in their egg cartons for too long, waiting for the weather to heat up. Seedlings should be moved to the garden once the roots reach the bottom of the tray, but before they start to grow into a circle.

Is February too early to start seeds indoors? ›

Most seeds require about a 6-8 week growing period before they're ready to be transplanted, which means the bulk of your indoor seeding should happen in February (early-to-mid February for Alexandria, and mid-to-late February for Lothian).

Is March too early to start seeds indoors? ›

March is the perfect time to get those tomato and pepper seeds started indoors so they can be ready for an early spring planting! Also now is a great time to start planting cool weather vegetables that can withstand those last frost days of March and April.

When should I start seeds indoors zone 6? ›

Q1: What is the best time to start seeds indoors in Zone 6? The optimal time to start seeds indoors largely depends on the specific plant variety. However, as a general rule, we recommend starting most seeds 6-8 weeks before the last frost date.

When to start seeds indoors in zone 8? ›

August
  1. Start seeds indoors for heading cole crops for your fall garden now. ...
  2. Sow peas in mid to late August for a fall crop.
  3. Finish starting seeds inside for fall crops like Brussels sprouts, and other heading Brassicas.
  4. Warmer parts of this zone can plant a fall crop of potatoes.

References

Top Articles
Latest Posts
Article information

Author: Wyatt Volkman LLD

Last Updated:

Views: 5953

Rating: 4.6 / 5 (66 voted)

Reviews: 89% of readers found this page helpful

Author information

Name: Wyatt Volkman LLD

Birthday: 1992-02-16

Address: Suite 851 78549 Lubowitz Well, Wardside, TX 98080-8615

Phone: +67618977178100

Job: Manufacturing Director

Hobby: Running, Mountaineering, Inline skating, Writing, Baton twirling, Computer programming, Stone skipping

Introduction: My name is Wyatt Volkman LLD, I am a handsome, rich, comfortable, lively, zealous, graceful, gifted person who loves writing and wants to share my knowledge and understanding with you.