There are several strategies for determining when to plant your garden. First of all, you need to figure out your areas last frost date. You can find a variety of calculators online that will give you the Average Last Frost Date for your zip code. We like the one from Farmer’s Almanac. Some of the dates they estimate for areas in and around Spokane are listed below.
Based on the average last spring frost date, you can estimate when you should be planting certain crops. Of course, these are ESTIMATES and AVERAGES. It’s absolutely critical to watch the forecast or you may end up suffering losses due to unexpected late frosts.
Once it get’s close to planting time, there are a few other metrics the long-time gardeners in Spokane use to determine if it’s time to plant. One is Mother’s Day. Usually, if you’re in Spokane or one of it’s suburbs, it’s safe to plant around Mother’s day. Again, be sure to keep an eye on the weather forecast.
One other metric used by the old timers is the snow on Mica Peak and Mt. Spokane. Once the snow is completely melted (as in what you can see from a distance i.e. the I-90 and Broadway looking NE) you should be safe to plant. I like that metric because it’s a visual reminder of how slowly things warm up when I’m chomping at the bit to plant.
| General Area | Last Spring Frost 2025 | First Fall Frost 2025 | Estimated Length of Growing Season |
|---|---|---|---|
| Spokane | May 1 | Oct 7 | 158 Days |
| Spangle* | Jun 13 | Aug 30 | 77 Days |
| Cheney | Jun 13 | Aug 30 | 77 Days |
| Deer Park | May 31 | Sep 7 | 98 Days |
| Liberty Lake | May 1 | Oct 7 | 158 Days |
| Nine Mile Falls | May 17 | Sep 19 | 124 Days |
| Airway Heights | May 17 | Sep 19 | 124 Days |
| Newport | May 18 | Sep 15 | 119 Days |
| CDA | Apr 29 | Oct 12 | 165 Days |
*The dates for Spangle and Cheney seem to possibly be a little off. There are definitely low areas where the cold tends to settle in and around Spangle. It's important to know your area and watch your thermometer and the weather forecast.
Once you’ve figured out your last estimated Spring Frost Date and downloaded a reliable weather app to keep an eye on the forecast, you can start figuring out about when you should plant certain crops based on that date. Some crops should be in the ground just a little ahead of the last spring frost and some well after. The chart below includes recommendations for various crop types.
| Crop Type | When to Start Seeds Inside | When to Transplant Starts | When to Direct Sow |
|---|---|---|---|
| Strawberries | 14-16 Weeks before average last frost date | 8-12 Weeks before average last frost date | — |
| Eggplant | 10-12 Weeks before average last frost date | 2-4 Weeks after average last frost date | Direct Sowing Not Recommended |
| Rosemary | 10-12 weeks before average last frost date | 1-2 Weeks after average last frost date | Direct Sowing Not Recommended |
| Dill | 8-10 weeks before average last frost date | 1-2 Weeks before average last frost date | 1-2 Weeks before average last frost date |
| Peppers | 8-10 weeks before average last frost date | 2-4 Weeks after average last frost date | Direct Sowing Not Recommended |
| Cabbage | 6-8 weeks before average last frost date | 4-6 Weeks before average last frost date | 4-6 Weeks before average last frost date |
| Oregano, Thyme, Sage | 6-8 weeks before average last frost date | 1-2 Weeks after average last frost date | Direct Sowing Not Recommended |
| Basil | 4-6 weeks before average last frost date | 1-2 Weeks after average last frost date | 1-2 Weeks after average last frost date |
| Broccoli | 4-6 weeks before average last frost date | 4-6 weeks before average last frost date | 4-6 weeks before average last frost date |
| Napa Cabbage | 4-6 weeks before average last frost date | 2-4 weeks before average last frost date | 2-4 weeks before average last frost date |
| Cauliflower | 4-6 weeks before average last frost date | 1-2 weeks before average last frost date | 1-2 weeks before average last frost date |
| Chamomile | 4-6 weeks before average last frost date | 4-6 weeks before average last frost date | 4-6 weeks before average last frost date |
| Ground Cherry | 4-6 weeks before average last frost date | 2-4 Weeks after average last frost date | Direct Sowing Not Recommended |
| Kale | 4-6 weeks before average last frost date | 1-2 weeks before average last frost date | 1-2 weeks before average last frost date |
| Lettuce | 4-6 weeks before average last frost date | 2-4 weeks before average last frost date | 2-4 weeks before average last frost date |
| Swiss Chard | 4-6 weeks before average last frost date | 2-4 weeks before average last frost date | 2-4 weeks before average last frost date |
| Tomato | 4-6 weeks before average last frost date | 1-2 Weeks after average last frost date | Direct Sowing Not Recommended |
| Peas | Starting Inside Not Recommended | Starting Inside Not Recommended | 4-6 weeks before average last frost date |
| Radish | Starting Inside Not Recommended | Starting Inside Not Recommended | 4-6 weeks before average last frost date |
| Spinach | Starting Inside Not Recommended | Starting Inside Not Recommended | 4-6 weeks before average last frost date |
| Cucumber | 2-4 Weeks before average last frost date | 1-2 Weeks after average last frost date | 1-2 Weeks after average last frost date |
| Melon | 2-4 Weeks before average last frost date | 1-2 Weeks after average last frost date | 1-2 Weeks after average last frost date |
| Pumpkin | 2-4 Weeks before average last frost date | 2-4 Weeks after average last frost date | 2-4 Weeks after average last frost date |
| Spinach | 2-4 Weeks before average last frost date | 4-6 weeks before average last frost date | 4-6 weeks before average last frost date |
| Squash (summer and Winter) | 2-4 Weeks before average last frost date | 2-4 Weeks after average last frost date | 2-4 Weeks after average last frost date |
| Arugula | Starting Inside Not Recommended | Starting Inside Not Recommended | 2-4 Weeks before average last frost date |
| Beet | Not usually started inside; 4-6 weeks before average last frost date | 2-4 Weeks before average last frost date | 2-4 Weeks before average last frost date |
| Carrot | Starting Inside Not Recommended | Starting Inside Not Recommended | 2-4 Weeks before average last frost date |
| Greens | Not usually started inside; 4-6 weeks before average last frost date | 2-4 Weeks before average last frost date | 2-4 Weeks before average last frost date |
| Beans | Start inside on your Average Last Frost Date | 1-2 Weeks after average last frost date | 1-2 Weeks after average last frost date |
| Corn | Starting Inside Not Recommended | Starting Inside Not Recommended | 1-2 Weeks after average last frost date |
| Cabbage (fall) | 2-3 Months before average first fall frost date | Mid July |
One thing you may notice from these charts, there are very few crops you will plant on or immediately around your last estimated spring frost date. Cool season crops like cabbage, spinach, peas, and carrots do best planted a little ahead, and heat loving crops like peppers, tomatoes, and squash will be far happier if you delay getting them into the garden just a bit.