How to Direct Sow with Worm Castings
Are you wanting to spend more time in the garden this Summer, but not entirely sure how to turn seeds into beautiful plants? It was only a few years ago I was in the same shoes - dumping packs of seeds and hoping for the best. But, through a few years of experimenting I've learnt which factors are most important to successful Direct Sowing. So in hopes of saving you a few years of trialing, today I'm going to share my tips to Direct Sowing and why worm castings are so beneficial to the process!
What is Direct Sowing?
Direct sowing is a term used to describe the action of planting seeds directly into the garden beds, rather than starting them indoors under the grow lights and later transplanting them into the garden.
As such, one benefit of direct sowing is that it can save you time and money by eliminating the need to purchase the supplies to start seeds indoors.
Additionally, direct sowing can help reduce the risk of transplant shock, which can occur when plants are moved from one environment to another. If you're thinking of trying direct sowing this season, be sure to do your research to understand the key factors to success and how it differs to indoor seed starting!
Direct Sowing vs Indoor Seed Starting
There are three specific scenarios when I will elect to direct sow seeds instead of starting seeds indoors under the grow light:
- Fast Crops: Certain crops, such as Radishes and Spinach, have a growing cycle of only 30-60 days until harvest. Because of how fast their growing cycle is, it's easier to simply direct sow them into the garden rather than starting them indoors, potting them up, hardening them off, and transplanting them into the garden. Save yourself the time and direct sow these fast crops!
- Rooted Crops: Other crops, such as Carrots, Parsnips, Turnips, and more, have a distinct tap root. This tap root is going to quickly shoot down as deep into the soil as it can rather than staying shallow and branching out. Because of this, if it is in a seed cell under grow lights it will hit the bottom of a large 3.5" seed cell within 10-14 days. As this occurs, the vegetable is more likely to grow in an irregular shape, opposed to the straight and long shape we're used to seeing.
- Forgot: And lastly, every season there are certain seeds I forget to start! For those that take a longer time to mature and harvest (such as tomatoes, peppers, etc.) I will simply buy seedlings. But those that have faster growing cycles I will simply direct sow the seeds into the garden. I know we've all found ourselves in this position before!
What seeds should you Direct Sow?
If you have read our guide on Hardening off and Transplanting, then you know the outdoor garden is much more intense and variable than the indoor environment. The temperature will fluctuate significantly, wind will dry the soil more quickly, and the sun is about 10x more intense than our indoor grow lights.
Because of this, we want to start seeds that are going to be more hardy and able to withstand this intensity and variability, while keeping our more fragile plants (such as peppers and squashes) for the indoors and transplanting.
Furthermore, we need to wait until the soil is warm enough for seeds to germinate for direct sowing. Because of this, it's best to direct sow our fastest crops while giving the slower growing crops a head start by starting them indoors either a few weeks or months earlier.
A few of the best crops to direct sow include Radishes, Arugula, Carrots, Beets, and more!
This combination or direct sowing and indoor seed starting will give you an abundant and much more productive garden than direct sowing all seeds.
When do you Direct Sow seeds?
For seeds to successfully germinate, they need to be in a warm and moist environment. As such, the timing will vary for each of us depending on our growing zone. To determine when to direct sow seeds for yourself, simply follow these steps:
- Seeds: Determine the seeds you want to start. I always recommend growing what you love and that will bring you joy!
- Growing Zone: Search the name of your city and Growing Zone (i.e. Vancouver Growing Zone). This will tell you which growing zone you're in (i.e. Zone 8b).
- Planting Chart: Search your growing zone and the words Planting Chart (i.e. Zone 8b Planting Chart). You will likely come across multiple planting charts for your Zone - pick your favorite!
- Plan: Go through the planting chart and look up each seed you want to start and make note of its recommended starting date. And voila - you now have a plan for when you'll be starting each of your seeds!
If you're gardening in Canada, then West Coast Seeds has an amazing set of planting charts and you can find yours here.
Tips for Direct sowing
So with your seeds on hand and direct sowing dates determined, how do you actually get them started? Here are a few of my favorite tips that help me get nearly a 100% germination rate:
3 Seeds Per Space
Why Worm Castings are so beneficial to Direct Sowing
Worm castings are my secret to getting such a high germination rate.
One of the most talented horticulturalists I know would cover her seeds with vermiculite because it retains water so well. However, she shifted to utilizing worm castings because it not only has incredibly high moisture retention, but because it has the added benefit (that vermiculite wouldn't) of providing microbial life and biology directly around the seed as soon as it germinates.
As a result, you get not only incredible moisture retention but also microbial life interacting with your germinating seed from the moment it sprouts which will result in it growing bigger, more lush, and more resilient to pests and diseases.