Skip to main content

This is when you should start seeds indoors

Everything you need to know about timing your seed-growing journey

Seedling growing from soil
Nikolett Emmert / Unsplash

For gardeners, late winter can be an exciting time of year. When the weather gradually warms up, that means that you can finally start your seeds indoors. Even if the temperatures aren’t quite warm enough outside, you can grow seedlings to transplant into your bountiful garden for spring. But if you’re wondering when to start your seeds indoors, you’re definitely not alone. To give your seedlings the best chances of survival, here’s what you need to know about timing your seed starting. 

Seedlings in plant tray
Markus Spiske / Unsplash

Why you should wait to start your seeds

In the winter, cold soil temperatures make it difficult for plants to get the water and nutrients that they need in order to grow healthy and strong. Even if your plants do grow, they can be prone to disease and cold damage. Unless you’re using a greenhouse or live in a warm climate, it’s probably best to delay growing anything outside until after the last frost. You especially want to delay growing your annuals too early, as they’re not suited to grow out in your climate zone all times of year. 

Recommended Videos

Starting your seeds indoors gives you a bit of time to get them ready before the last frost. This approach allows you to control germination aspects such as light and temperature. You can take advantage of your warm indoor conditions and transplant your seedlings outside when outdoor temperatures are suitable for planting. Just keep in mind that not all seeds can be started indoors. 

Some plants, such as carrots, do not handle transplant shock well, so you need to start them outside. The timing for when you should do so varies from plant to plant, but seeds for cold-season veggies, like carrots, should be sowed a few weeks before the last frost. When in doubt, look up your plant’s seed-starting requirements to ensure healthy plant growth. 

Growing seedling
Francesco Gallarotti / Unsplash

The best time to start seeds indoors

Read your seed packet carefully to figure out the best approach for growing your plant. Typically, seed packets will suggest starting your plant indoors four to six weeks before the last frost. There are plenty of websites online that allow you to look up your last frost date, including Old Farmer’s Almanac. You simply input your zip code to figure out your prospective last frost date. 

After starting your seeds indoors, be sure to give your growing seedlings plenty of warmth and bright indirect sunlight. Keep your seed-starting mix moist but never soggy. In some cases, it may be helpful to create a humidity dome around your seed starter tray. Some plants, such as tomatoes and peppers, also appreciate a warm heat mat.

Remember that it’s a safer rule of thumb to start your plants a little late in warm temperatures than too early in frost-impacted soil. Sowing your seeds for spring can be exciting, but you want to get your timing just right. Starting them indoors can help you control a wide range of factors, namely light and temperature, so that you can enjoy a lush harvest with as few bumps in the road as possible. 

Stacey Nguyen
Stacey's work has appeared on sites such as POPSUGAR, HelloGiggles, Buzzfeed, The Balance, TripSavvy, and more. When she's…
Our favorite desert plants you will love
Grow these desert plants for a drought- and heat-tolerant garden
Variety of succulents

Some people may imagine deserts as barren wastelands, but that’s not quite the truth. There are actually plenty of plants that are adapted to hot, dry climates. These plants can have thick leaves or stems that can store water, or they might spend a lot of time dormant while waiting for the next burst of rain.

Desert plants, including most types of cacti, are varied and beautiful. If you live in a desert climate, growing desert plants makes gardening and landscaping much easier. To help you get started, here are our favorite desert plants that you should try growing.
Desert rose

Read more
6 types of gourds you should know this fall season
Gourds that add seasonal spirit to your fall garden
A variety of squash types set on a black table

From pumpkins to watermelons, there are many incredible gourds you can grow in your garden. While some gourds are ready to be harvested in summer or winter, fall is the season most often associated with gourds -- and for good reason. Some of the most popular fall decorations are gourds, including pumpkins and many types of squash. What should you do if you want something a little more unusual, though? We have a list of six fun and unique types of gourds you should know about to get you started.
Speckled swan gourds

Speckled swan gourds are a type of calabash or bottle gourd, named for their distinctive shape. With a round base and long, curved neck, they resemble swans when placed upright. Speckled swan gourds are typically dark green with lighter green or cream-colored speckles or markings.

Read more
How to plant pumpkin seeds: A step-by-step guide
Plant the pumpkin patch of your dreams
A small pumpkin sitting on top of a fence post

Pumpkins are an incredible seasonal fruit. Whether you prefer to grow them to use in pies, as decoration, or simply because you like the way they look on the vine, there’s no denying that pumpkins are lovely and rewarding to grow. While you can get pumpkin seedlings at some nurseries, most gardeners start with pumpkin seeds. Not sure how to plant pumpkin seeds? We’ll walk you through everything you need to know.
Picking the right pumpkin variety

Before you plant your pumpkins, you need to choose the best variety for your garden. Most choices will be based on your preferences, such as color, shape, and texture. There are many fascinating pumpkin varieties, from solid white pumpkins to bumpy green ones, and of course, the many varieties of classic orange pumpkins.

Read more