Prepare moving plants outdoors – “Mise en place” for home gardeners

Come spring; most plants move outdoors. And here, you need to get organized. This holds true if you start plants from seeds or buy seedlings at a local nursery.

As home gardeners, we can learn a lot from professional chefs. “Mise en place” is a French culinary term that means we should have everything prepared and in order before starting.

In the kitchen, it may include peeling, cutting, and measuring ingredients. For us home gardeners, it means planning carefully before we start moving plants outdoors.

This article will take you through how I prepare my pots, container, and grow bags before I move my tomatoes, eggplants, peppers, and other herbs and vegetables outdoors.

Mixing the filler layer of soil, old mulch, and a few slow-release fertilizers
Mixing the filler in a large container

But before we move on to the process, here are two important notes:

  1. Minimum temperature and weather
    Before moving my plants outdoors, I wait for the minimum temperature to be above 10 degrees Celsius / 50 degrees Fahrenheit. And I avoid days with a lot of wind.
    I have learned the hard way that windy conditions can do real damage to plants, with leaves turning white, crumbling, and dying. Patience can be a virtue. 
  2. Don’t move all plants at the same time
    There are always things that you cannot control. And if you are unlucky, animals or bad weather can ruin your plants. 
    There is just no way to know. Move half your plants, observe, and then if all is well, move the rest. 
    Should you lose all your plants, move half of the remaining plants next time. 

And yes, this is one reason why it is always a good idea to plant a few more seeds than the number of plants you plan to grow.


How I prepare for moving plants outdoors (5 steps)

A couple of days before moving my plants outdoors, I spend a day preparing all receiving pots, containers, and grow bags. 

Being prepared makes the actual transplant or move outdoors simpler and faster. And this is a good thing, especially if you are moving many plants. 

Step 1. Get pots, containers, and grow bags in order

Collect and inspect your pots, containers, and grow bags.

I give most containers a quick scrub with a brush and a short clean with my garden hose.

If you have plants suffering from pests or diseases, move them aside and clean them properly before putting them to use again. 

Gardening in zone 7, winter and freezing temperatures helps eliminate some pests, but not all. [1]

Step 2. Fill the bottom with a well-draining fill layer

Quality gardening soil is costly, especially if you have many plants.

I prepare each pot, container, and grow bag to receive a specific plant. Plants that develop extensive root systems need more soil, while others with more shallow growing roots need less. 

In each receiving container, I add a well-draining filler layer made from mulch like hay or straw, soil, and slow-release fertilizer pellets. Next, I water thoroughly. 

Adding filler layer in each individual pot, container, and grow bag.
Adding filler in each container

How much filler do you add?

It depends on the size of the container and the type of plant I am growing. 

I will give you two real-life examples to illustrate. 

1. Cherry tomatoes: 

Except for mini-varieties growing in hanging baskets, I give my cherry tomato plants in pots a minimum of 20 liters (5 US gallons, 4.4 Imperial gallons) of soil.

Some of my pots hold 30 liters; here, I would add a 5-10 liter filler layer.

Keep in mind that the filler layer will compact if it is porous.

2. Leafy greens like lettuce and arugula, and rocket:

Lettuce and other shallow root crops need less soil depth than ghost peppers or beefsteak tomatoes to grow and thrive. In that same 30-liter container, I would fill all but the top 3-4 inches with my filler layer of organic material.

Why use a filler layer and not just soil?

Using a filler layer in the bottom of your container will save you money and helps control soil moisture.

Let me give you an example.

I mulch all my garden beds when the growing season is over. Some of the mulch breaks down over winter and is turned into the soil using a garden spade. But some of the mulch still sits on top of the garden bed. 

Come planting time, I collect the mulch still sitting on top, mix it with soil and a handful of slow-release fertilizer pellets, and just like that, I have my ideal 100% organing filler layer for free. 

But it is not all about saving money. Using too much soil for any given plant also complicates controlling soil moisture

If you grow a shallow root vegetable in a deep pot, you risk the soil drying out on top but remaining moist or even wet deeper down. If your water again, you will create a growing environment where the bottom of the container is soaking wet, risking root rot and other problems. 

Step 3. Add soil same day

The filler layer is, by definition, porous a will attract snails, slugs, and other unwanted guests if left to dry out in the open. At least, I have found this to be true in my garden.

When I have watered the filler layer thoroughly, I fill the pot, container, or grow bag with soil to no more than ¾ of its capacity. 

Adding soil to each container, pot , and grow bag the same day
Adding fresh soil on top of the filler layer

The goal here is to cover the filler layer completely.

I leave at least ¼ open for fresh soil to be added on the day of the actual move or transplant.

Step 4. Add perlite for improved drainage and soil aeration

Next, I add perlite to improve drainage and soil aeration and gently wet the perlite with water.

Always be mindful of the dust when working with perlite. It is harmful to inhale the dust. Use gloves and check the direction of the wind before you start. 
Adding perlite improves soil aeration and drainage
Perlite improves soil aeration and drainage

Ensure the perlite is wet as it binds the dust, but you do not want the soil soaking wet. Soaking wet soil makes it difficult to mix in the perlite. 

When the perlite is wet, mix it into the soil. 

Step 5. Water

Now all that is left to do is to water thoroughly. I find a long-reach garden hose nozzle sprayer ideal for the job.

Moisten the perlite and then water containers thoroughly when done
Moisten perlite, mix, and then water thoroughly

That’s it – you now have a home ready for the plants you plan to move outdoors.

This “mise en place” approach works well for me and helps me work more effectively and faster.

I hope it will do the same for you.

FAQ

Summary and recommendation

Here is my best tip for you. Always start more plants than you plan to grow if you are a beginner home gardener or are growing a vegetable or herb for the first time.

Whenever you doubt whether you should water or fertilize, water or fertilize only half your plants and observe. 

It is the only way to learn what works in your garden.

Reading articles like this will give you a framework, but the details come from experience. 

So, do not fear losing a few plants on your way to honing your skills as a home gardener. It is all a part of your journey to becoming the master home gardener in your growing space.

The framework I have given you is a step in the right direction, but fine-tuning will always come from experience. 

I wish you a great growing season in your garden!

Helpful sources:

[1] https://extension.entm.purdue.edu/newsletters/pestandcrop/article/did-insect-pests-freeze-with-recent-low-temperatures/

Meet the author: Mattias is an experienced gardener spending most of his free time on his knees among herbs, plants, and garden vegetables. For the past two years, he has been sharing gardening projects and how-to tutorials on the NordicLavender website and YouTube channel.