When to start garden seeds indoors: Seed starting calculator
8.8 years ago cheap, indoor growbox, indoor seed starting, seedling, seeds
When you start seeds indoors in a vegetable garden, it can be difficult getting your schedule down to ensure that start your vegetable seeds with enough lead time that they are mature enough to venture outside but also not so large they take over your growing area.
Personally this has been a difficult part for me where I am really good getting the early vegetables started on time (onions, peppers, tomatoes) but when it comes to the later plants and/or second/third plantings is where I begin to get forgetful. Over the years I have come across a couple of great tools to make this easier that I thought I would share.
No matter which option you choose to start garden seeds indoors you will need to determine an important date, your last frost date. There are many sites/tables out there that will give an estimate I actually have a couple posts on the subject but at the moment my favorite site that makes this very easy is WeatherSpark, it uses historical data with great visuals to easily determine when the best probability of picking the right date. Here you can take a look at this historical data and make your call of what date you think will be safe.
1. Create a garden schedule. Just by figuring out your last frost date and doing a little math (Excel works great for this) you can determine the optimal seed starting dates and even get a general idea of when your plants should be ready for transplanting. What I love about this technique is you can tweak it each year as things worked well (or not so well) in previous years to get the schedule finely tuned to your particular garden and the micro-climates within it.
In addition knowing an estimate of when these plants will be venturing out in the wild can assist in your space planning for your seeding area as well as having a reality check if you see your peppers will be ready to be transplanted in March when it doesn’t get above freezing until mid-June.
Here is my schedule for starting seeds indoors my area and estimated last frost date (April 20th), though sure everyone that is reading this will not have the same date as mine so thanks to my infinite nerdiness I made the following table so you can adjust the “Last Frost Date” to yours and see how my schedule would look in your area.
Last Frost Date: |
Vegetable Name | Seed Start Date | Estimated Transplant Date |
Estimated Harvest Date |
Celery | 1/19/2013 | 3/18/2013 | 4/24/2013 |
Onion | 1/19/2013 | 3/25/2013 | 5/24/2013 |
Leeks | 1/19/2013 | 3/21/2013 | 6/3/2013 |
Kale | 1/26/2013 | 3/7/2013 | 3/22/2013 |
Artichoke | 1/31/2013 | 4/27/2013 | 6/20/2013 |
Kohlrabi | 2/9/2013 | 3/15/2013 | 4/5/2013 |
Pak Choi | 2/9/2013 | 3/6/2013 | 4/10/2013 |
Parsley | 2/8/2013 | 4/6/2013 | 4/24/2013 |
Lettuce | 2/9/2013 | 3/6/2013 | 4/5/2013 |
Broccoli | 2/9/2013 | 3/15/2013 | 4/20/2013 |
Pepper – Jalapeno | 2/9/2013 | 4/28/2013 | 4/25/2013 |
Pepper – Bell | 2/9/2013 | 5/4/2013 | 4/25/2013 |
Swiss Chard | 2/16/2013 | 3/20/2013 | 4/7/2013 |
Cabbage | 2/16/2013 | 3/31/2013 | 5/7/2013 |
Brussel Sprouts | 2/22/2013 | 3/31/2013 | 5/23/2013 |
Collards | 3/2/2013 | 3/24/2013 | 5/1/2013 |
Tomato | 3/2/2013 | 5/4/2013 | 5/21/2013 |
Spinach | 3/9/2013 | 4/23/2013 | |
Peas | 3/9/2013 | 5/13/2013 | |
Turnips | 3/9/2013 | 5/8/2013 | |
Watermelon | 3/16/2013 | 5/27/2013 | 6/14/2013 |
Basil | 3/24/2013 | 5/14/2013 | 6/22/2013 |
Potatoes | 3/30/2013 | 7/8/2013 | |
Radish | 3/31/2013 | 5/5/2013 | |
Beets | 3/31/2013 | 6/4/2013 | |
Carrots | 4/9/2013 | 6/23/2013 | |
Corn | 4/9/2013 | 5/7/2013 | 6/28/2013 |
Cucumber | 4/9/2013 | 5/16/2013 | 6/8/2013 |
Okra | 4/9/2013 | 5/11/2013 | 6/13/2013 |
Pumpkin | 4/9/2013 | 5/7/2013 | 7/28/2013 |
Summer Squash – Sunburst | 4/9/2013 | 5/16/2013 | 6/3/2013 |
Winter Squash – Hunter | 4/9/2013 | 5/16/2013 | 7/3/2013 |
Zucchini | 4/9/2013 | 5/16/2013 | 6/3/2013 |
Lettuce | 4/13/2013 | 6/7/2013 | |
Beans | 5/4/2013 | 7/13/2013 | |
Dill | 5/11/2013 | 7/15/2013 | |
Carrots | 5/27/2013 | 8/10/2013 | |
Broccoli | 6/22/2013 | 8/2/2013 | 8/31/2013 |
Cabbage | 6/22/2013 | 8/2/2013 | 9/10/2013 |
Kale | 6/22/2013 | 7/22/2013 | 8/16/2013 |
Kohlrabi | 6/22/2013 | 7/29/2013 | 8/16/2013 |
Cabbage – Napa | 7/24/2013 | 8/21/2013 | 10/7/2013 |
Pak Choi | 7/24/2013 | 8/21/2013 | 9/22/2013 |
Onion – Bunching | 7/24/2013 | 10/2/2013 | |
Turnip | 7/24/2013 | 9/22/2013 | |
Lettuce | 8/3/2013 | 9/27/2013 | |
Spinach | 8/10/2013 | 9/24/2013 | |
Corn Salad | 8/10/2013 | 9/29/2013 | |
Garlic | 10/12/2013 | 2/14/2014 | |
Pak Choi | 12/14/2013 | 1/26/2014 | 2/12/2014 |
* N/A because vegetables should be sown directly in the ground.
2. Create a garden plan online and get reminders. My favorite online vegetable gardening software is GrowVeg. It is very easy to use and provides some great visuals when to specifically plant seeds and transplant your seedlings outdoors, which you can see below.
In addition you also can recreate a virtual copy of your garden and plan exactly where you want to plant your vegetables, to ensure your ambitions for growing a huge crop this year does not exceed the reality of the limited space you have to actually grow. It also remembers where you planted vegetables in previous years to help enforce crop rotation to ensure pests/diseases will be forced to remain in check.
Though one of my favorite features is the weekly reminders, once a week you get a simple email letting you know what plants you should be starting/transplanting that week. This was very helpful later in the season where I probably would have completely forgotten about my carrots without this helpful reminder.
3. Buy a garden planning book. If you want something that you can really get your hands on you might want to check out the Week-by-Week Vegetable Gardener’s Handbook helps with this problem by providing weekly reminders of what vegetables you should be order/planting and what preparations you should be doing in your garden. This can be a very helpful tool in getting a little more organized in your vegetable garden.
Already falling behind on your seed planting here are a few great options to get a great selection of seeds without spending a lot of money:
- One of my favorites is Burpee Seeds, they have been around since 1876 and definitely know their stuff. The actually have a seed sale going on now where you get $15 off on order of $75 (just use code AFFB4A35) expires on 1/15.
- The name is not too exciting but Generic Seeds offers no thrills packaging with quality seeds and very reasonable prices and if you spend $20 or more shipping is on them.
11.9 years ago
This is a great resource, thanks! !
In your excel table, your dates for Pepper – Jalapeno and Pepper – Bell are wacky. Transplant to harvest days are -3 and -9 respectively.
Cheers, Ken
11.9 years ago
Ken, good eyes. Looks like I fat fingered that one should make more sense now…
11.9 years ago
Great article! And great site you have. I will definitely get back frequently 🙂
11.8 years ago
The spreadsheet is helpful. Thanks.
11.7 years ago
This is great and I am currently following it. I wonder if you could add eggplant and a few other herbs to the list (e.g., cilantro, mint, chives).
11 years ago
[…] Hope you have a happy holiday and for those looking to get started with your garden don’t fret there are seeds you can start indoors soon. If you wondering what you can start planting in Dec/Jan in your area check out of seed starting calculator. […]
11 years ago
Your calculator is phenomenal! So helpful! Instantly did a better job than I’ve been doing for years. Thanks for sharing your method.
11 years ago
Glad it looks like it will work for you, start dates worked excellent for me last year. Probably will do some enhancements this year so open to suggestions.
11 years ago
[…] Seed start schedule […]
10 years ago
[…] Seed start schedule […]
9.9 years ago
Found your work quite interesting. Your interactive last frost chart date is a great idea. The seed planting dates and transplant dates are right on.
Did have a question regarding the harvest date for tomatoes. My understanding is that days to maturity in the catalogs and on seed packets is the time interval from transplant to harvest. The shortest date is around 55 days up to 85 days plus.
The chart shows the interval from transplant to harvest is 17 days.
Regards,
Lee
9.9 years ago
Lee, you are very correct must have a number fat fingered there will fix that tonight…
9.8 years ago
Thank you for the seed starting schedule! This was a great find for me and right on time. The information on the entire page is very helpful! What is the significance of the colors in your seed starting schedule?
9.8 years ago
Colors are just so you can quickly identify which plants you start around the same time…
9.1 years ago
i am need software grow box system and books for vegetable gardener
8.8 years ago
Great information.&
8.8 years ago
What about parsnips? They don’t seem to be on the chart.
8.8 years ago
Great and very helpful post! I’m done with most of my seed starters, but my sister is just beginning, so your post is exactly what she needs. In fact all these charts and graphics and very helpful at all. Thank you for sharing all this great and very useful information! Happy gardening!
8.6 years ago
That Last Frost Date Chart is amazingly helpful! Thank you!
8.5 years ago
Very organized and great post =) These are incredibly helpful!
8.5 years ago
Talk about bringing gardening to the 21st century. I didn’t think it would matter when your start if you grew your vegetables indoors I see now it does.