Wait, Are Raised Beds Right for Your Space? Here’s How to Tell

An excerpt from this piece originally appeared in our newsletter, “Sunset 101: The Ultimate Guide to Raised Beds.” To find out more about Sunset’s newsletters, click here.

New Mexico landscape designer Judith Phillips was probably not surprised when we reached out to her asking for gardening advice. After all, she’s well respected in her field and knew how much we adore a project she recently worked on, renovating and replanting the grounds of the Los Poblanos inn and farm, outside of Albuquerque. (We admired this project enough to feature it in our 2022 Garden Issue.)

But living as she does in a place with large seasonal temperature extremes, she’d always considered plants to be best off in the ground, insulated by the earth, not a few inches of dirt in a box. She also was wary of how much water raised beds require. “I’ve always sort of had a negative bias to raised beds,” she admits. Still, two experiences helped her come around to the idea. One is realizing that her own property is crisscrossed with enough buried utilities that digging in crops would be impractical, so she raised up some beds in her own yard and saw them thrive. 

She also oversaw several magnificent 24-foot long raised beds that were installed on the grounds of Los Poblanos. These beds were only raised because the plants in them needed to be sheltered from runaway balls popping out of nearby petanque courts, but they’ve done beautifully. “So, you know, there are just all kinds of reasons both for using raised beds and for not using raised beds, depending on what the situation is,” Phillips concedes.

Raised beds will freeze more readily than something in the ground, right?

Oh, yeah. In a raised bed the entire root system will freeze. And you know, depending on the plant, if it gets to be 50°F during the day, it may thaw quite a bit but at night it’ll freeze again. And it’s not just the freezing. I know that in the summertime for about six inches in from the side walls of the bed, there are no roots, because they burn off. 

One of the things I really like about growing food crops in the ground is that you can bury the green waste from your kitchen in between the rows and then the next year you can alternate where the rows are, and you are amending the soil and eliminating the water you’d have to use to compost, so it’s a whole lot more efficient. 

I suppose you could do that in a raised bed. I’m actually experimenting with that. I have been burying some green waste in beds to try and mulch with leaves and let them decompose, trying to forestall having to uproot the plants that are in there to change the soil.

How do you make the decision about where a raised bed should go? Are you looking for a flat spot? Is the light the most important consideration? 

It varies with what they [the clients] want to grow. If they wanted to grow corn or squash, I would put those crops in the ground, because corn’s a heavy feeder. I will suggest to people that if they put in a vegetable garden, especially raised beds, make them east-facing or north facing so that they’re buffered some from the hottest part of the day. And definitely put them where there’s easy access to water because there’ll be watering, sometimes daily. 

I wonder that the first steps are. It makes sense that it would be to pick what you’re going to grow. Is that true? 

There are a lot of considerations that go into making that choice generally. Some of my clients will want to grow food crops, others not, and the most difficult is people who want to grow a lot, especially fruit trees or something that actually takes a considerable amount of space. 

One way of maximizing space is that I recommend semi-dwarf fruit trees, because they stay a manageable size. Space those 14 feet apart, and put a raised bed in between, so that any water that drains through the soil of the raised bed is available to the fruit trees. And as the trees start developing a larger canopy, the need to buffer the beds is a lot less than if they’re in the open.

More from this issue:

• Need Help Taking Care of Your Air Plants? We’ve Got Just the Guy
• Stroll Through Lotusland, the Fantastical Botanic Garden of Your Dreams
• What Happens When the West Coast Barbecue King Sets out to Conquer Fried Chicken?
• Add Some Color to Your Brunch with Edible Flowers

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If somebody wants to put in beds, would you recommend that they make their own? Do you recommend they buy some kind of a kit?

I haven’t found any kits that I would buy. But you know, it all depends. A lot of times people can’t afford to do a more expensive bed so they’ll buy a kit, or if they’re not going to live in a place very long, it doesn’t make sense to invest a lot. So yeah, like everything with gardening, it depends.

What kind of carpentry skills do you need? Do you need joinery? Or can you just kind of bang the corners together?

I suggest to people that are building their own beds that they use Trex or a comparable quality composite lumber. It’s better to screw them together than to nail them in this climate. Even screws will eventually pop out. The reason that I like the composite lumber is first of all it’s recycled materials, but secondly it’s inert, People sometimes will use pressure-treated wood. I don’t know that that’s such a good thing. That’s treated with copper arsenate, I believe, at least it used to be. Cedar is the other option and that’s expensive and it’s less available usually. 

I guess there are as many ways of working it as people have the resources and the time and the ideas to do. 

What’s your favorite thing to grow?

I don’t have one favorite thing. There are so many salvias that are just gorgeous like Mojave sage. Salvia pachyphyllais a plant that I really love because it has evergreen leaves and flowers for a long time. I also….ephedra is….I don’t know! It depends. Depends on the day or the week, or the time of day, I guess.

Do you have a favorite gardening tool?

I have a rake that collapses. It’s a fan rake and the tines can be six inches wide, or fan out to be 12 or more inches wide and I really like that tool for getting into small spaces. I also have a pair of Japanese shears for cutting ornamental grass back that I really love. ARS is the brand and the tool itself is a KR 1000. 

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