Warm the soil, plant salad veggies and other tips for your May long weekend gardening

The May long weekend is not only the unofficial start of summer, it's also often the weekend people buy plants for their gardens or containers.

Garden centres will be packed as people look for the perfect plant to grow, whether it's flowers, fruits, vegetables or other greenery.

Perry Grobe of Grobe Nursery and Garden Centre in Breslau, Ont., joined Craig Norris, host of CBC Kitchener-Waterloo's The Morning Edition, on Friday to offer people some tips on how to get started.

The following interview has been edited for length and clarity. 

Craig Norris: So this week we've seen some frost. I know you always say don't plant before the long weekend. Is it actually safe to start?

Perry Grobe: Shrubs and trees and bushes and things like that are absolutely safe to do right now. The things that are going to have some trouble are anything that's more of an annual nature, your vegetables. A lot of them will not take the cold temperatures at all and not just the air temperature, but they don't like the soil temperature being cold. 

If you've ever planted peppers and had them sit there … and not bear anything, it's usually because the ground is too cold for them. 

Now you can cheat a little bit. If your vegetable garden has black plastic garbage bags put over it, let the sun warm up that soil and it'll be much, much happier when you go around to planting.

Norris: I'm glad you brought up vegetables because people, it seems, now are so eager to grow their own food, right? Is that a trend that you're seeing any different this year?

Grobe: There's no question about it. Our vegetables, even the space we've allocated for it, has gotten a whole lot bigger and there's every possible thing that you could grow for yourself if you choose to, even in balconies or patio pots or whatever.

There's always a little something that you can grow to consume. Lettuce is a big one. Everybody knows what the cost of lettuce is, so there's lots of lettuce.

Norris: What are some of the best fruits or vegetables that can be grown in containers, say on a patio?

Grobe: To my mind, the things that you can get the most enjoyment out of are going to be the things that you can make a quick salad with, or you can spice up what you have with whatever you're cooking.

Herbs are really popular. Anything that goes into a salad is popular. Tomatoes you can buy now. Peppers for pots, you can buy cucumbers for pots. There's all kinds of things that are scaled down size-wise that you can grow and really have some success with in a smaller pot.

Norris: Now about herbs, what should [people] keep in mind? Because I've often seen them all grouped into one container.

Grobe: It's absolutely what you want. Because the thing is most people tend to overestimate how much they're going to use. Like other than basil, which you might use a lot, all of the other herbs you use in small amounts. 

So the little bit of herbs that you're doing, little chives, little this, little that, it's amazing. You have a pot with a multiple of a bunch of herbs in it and you will be more than set for the whole season. You don't need a whole lot.

Norris: What about flowers? People love to add colour to their houses. What are some good hearty species that are going to last longer than a week or so?

Grobe: Well, the nice thing is, is that the breeders have done a whole lot to make sure that a lot of these things are way better than anything ever before.

There was a period of time, not too long ago, that impatiens were problematic, they had a downy mildew disease. A lot of people suffered as a result of this disease.

The new seed strains they have out now are far more disease resistant. So folks that have kind of shied away from impatiens can certainly go back to them … especially for shady areas.

For me, it's a water thing. Some of the best for a little water are verbenas, lantanas, believe it or not geraniums tend to be very tough plants. 

Portulaca is another one that is a little less water demanding and still look beautiful in the summertime.

Norris: We talked on the show recently about finding native species when people go to the nursery. How do they know if a species is native to Waterloo region, or at least this part of southern Ontario?

Grobe: It's a great challenge to be able to answer that question because oftentimes, specifically grown to this area that are sold in this area, there really isn't all that terribly many that I can say right off the top of my head.

I would say that in the shrub forms, that's a little bit more evident to find. In the perennial forms, oftentimes there is, believe it or not, while there's interest, sometimes there's less demand and we can custom order anything that folks want that way.

Norris: People may get plants from the garden centres and they just pop them into their container or their garden, just whatever soil is there. What tips can you give us to improve the health of the soil that we're growing stuff in?

Grobe: Well, if it's a newer subdivision, oftentimes the soils tend to be a little bit sterile. They may not have the microbial action that is necessary. 

So using manures, using composts, there's even now granulated products that have biochar and other things that you can mix into the soil to really boost the organic matter. That's the thing that's really helpful, because if you have healthy soils, if the shows are good and you've done your best to try and improve them prior to planting, it makes your life a ton easier. 

The bottom line is if you plant in a hole and you find garbage, so fill, clay, bricks, whatever, you can't reuse it. Get rid of it. It has to be replaced with something that's more suitable for growing life.

LISTEN | Spring gardening tips with nursery owner Perry Grobe: