Asparagus and tomatoes are a match made for organic gardens. Both plants release chemicals that ward off the pests of the other.
Tomatoes contain solanine, a substance that happens to be toxic to the asparagus beetle. The height of the tomatoes also creates shade that will help prevent weeds from growing around our asparagus plants. Asparagus contains a chemical that deters nematodes (a small worm) that are known to damage the roots of tomato plants.
Together, asparagus and tomatoes protect each other from common garden pests, creating a perfect match for your garden.
Add Parsley to the Mix
Both tomatoes and asparagus will grow more full when planted in a bed that includes parsley. It is best to plant the parsley before the tomatoes so the young parsley plants have a chance to get enough sun and establish themselves before the tomato plants grow tall.
What About Basil?
Basil is not know to help asparagus, but it does help tomatoes develop a more darker color and more rich flavor. Planting basil around the edges of your asparagus / tomato / parsley bed can benefit your tomatoes and provide bees from their beautiful flowers.
The Layout of Your Garden Bed
When you create a garden of companion plants, it is important to make sure they are not spaced more than 1 foot apart. It is best to plant them all in one giant bed so that they can compliment each other underneath the soil in addition to the benefits they provide above ground.
If you use the square foot gardening method, you can plant one tomato in one square foot, one asparagus every square foot, and either 1 or 4 parsley per square foot (depends if you want giant full plants or narrow smaller ones).
A checkerboard model of asparagus and tomatoes alternating can work well if the asparagus is planted before the tomatoes. This allows the young asparagus enough time to establish itself before the fast growing tomatoes spring into their full height.
If you include parsley into the mix, you can plant the parsley and asparagus together the winter before you start your spring tomatoes. Just put the tomato cages in your garden bed when you plant your asparagus and parsley plants. This will allow the parsley and asparagus to grow roots around the spikes of the cage, and not be pierced by them later when you plant the tomatoes.