Kick-Off Spring with Seeding your Garden

March 24th, 2021

After being cooped up at home for almost a year, it’s a natural desire to want to get outside, do something productive, and start thinking about when to start seeding your garden. Plants and vegetables are two great planting options to destress and focus on something that makes you happy.  

Whether you have experience with seeding or not, here are a couple of guidelines on how to prepare your garden to be the best it can be.  

For starters, only plan for what you know you have space for. It’s easy to get carried away with buying tons of seeds, but if you only have room in your garden for a couple and you over plant, you’ll have overcrowding issues throughout the season.  

When you’re picking your garden location, make sure you choose somewhere with the right amount of sun based on the plants you intend to grow. Don’t forget to consider where your hose is to make maintenance easier! 


Picking your Seeds 

When deciding what seeds you’d like to plant, pick them early in the season so you can learn how to plant them, gather any materials needed and have plenty of time to plant. It may be helpful to sort your seeds in to cool-season and warm-season crops to help you keep track. 

  • Cool-season crop examples: peas, lettuce, cabbage, spinach and other greens 
  • Warm-season crop examples: tomatoes, peppers, eggplant, squash  


Should I start planting seeds inside or outside? 

Different vegetables may require longer periods to grow from seed, meaning you may have to start them inside. Others grow well outdoors and don’t need as much fuss to get them started. Most seed packets provide you with specific information about the seeds you’ve chosen and can help you gauge what you will need to do to be successful. 


Here is a quick guide to common fruits and vegetables: 

Type of Seed When to Plant Where to Start
Kale and Collard Greens Spring time and again late summer  Outside
Tomatoes Mid-March  Outside 
Peppers Late March or early April  Inside 
Onions  Mid to late March, until late April  Outside 
Herbs April  Outside in pots or beds 
Strawberries  Spring is good, but summer works along with fall  Outside 
Broccoli March or April  Inside
Zucchini Early April  Inside 
Rhubarb Spring Outside 


Average Last Frost Date in Colorado 

It is necessary to know the last frost dates of where you are planting your garden. The last frost date is a date in which it is determined there will most likely be no more hard freezes that season. This date helps you understand when to plant new plants and when it is ok to place existing plants outside again.  

  • In most parts of Colorado, the average frost date is between May 15 and May 30.  
  • For most of Denver proper, the average frost date is about May 15. Some families even have a tradition of planting warm-weather vegetable plants, such as peppers and tomatoes, on Mother’s Day.  


When to Plant in Colorado 

  • Warm-weather seeds should be started in mid-March, or early spring or summer. Many Coloradans remember St. Patrick’s Day as the time to start seeds. 
  • Cool-weather seeds can be started inside beginning in early February through the end of the month. Depending on the cold tolerance of the plant, they can be planted outside starting in mid-to-late March. Most seeds can be planted 2-4 weeks before the last spring frost. 


Growing a garden can be a great hobby for an individual, roommates, couples or a family. Gardening can be a fun summer activity and you’ll get to enjoy the fruits (and vegetables) of your labor later on if you have properly planned. Be sure to research different plants to see what pairs well together as well. For more tips and tricks on the best way to start your garden, subscribe to our newsletter and follow us on social media!