How to prepare soil for planting flowers

Preparing soil

Most of us know someone whose yard is alive with color during the summer and who made it look effortless. It did take work, however. It took a lot of work. If someone can make it look effortless then they know how to prepare soil for planting flowers.

Their work started early in the spring, even as the last of winter started to thaw away. Like most things in life, their early preparations paved the way for their little slice of summer paradise.

We’re going to let you in on their secrets so that you, too, can grow a garden full of beautiful, lush flowers. We’re going to provide you with a lot of handy tips for how to prepare soil for planting flowers.

Success in gardening requires tapping into both sides of your brain. You’re about to write a summertime symphony with plants. If you don’t approach it as a work of art, it’s going to sound painful. You also need to tap into your analytical abilities. In addition to biology and chemistry, there is a bit of math. It isn’t rocket science, but a little knowledge can go a long way.

Think of gardening as a process. It isn’t just a matter of making a hole in the ground, plopping in a starter, and watering. It’s not a complicated process, really just a series of steps. It’s important to know what those steps are, what benefits they provide, and why things are generally ordered the way they do.

It’s also important to not think of gardening as just a summertime thing. It’s a year-round activity. When we talk about preparing soil, we’re talking about an ongoing process. You are always preparing your soil.

At the heart of gardening is your growing medium. That’s a fancy way of saying your soil. Your dirt. We hope you love dirt. Dirt is life,

A key thing to keep in mind is that plants exist both above and below the surface. A lot of the success of your garden will depend on what happens below the ground because those flowers won’t bloom without a root system capable of delivering nutrients and water to the plant. That’s why we’re placing such an emphasis on your soil. 

Let’s start with a brief chat about dirt. What is it? What’s it made of?

There are three basic types of dirt. You’re probably familiar with sand, which is one of them. It’s comparatively large bits of crushed rock. Of the soils, it is the most loosely packed. On the other end of the spectrum is clay, which consists of very small particles. It is the densest dirt type. In between the two is silt. The particles of silt are smaller than sand but larger than clay. Silt is superior to the other two in one important way. It is better at holding moisture.

The best medium for growing things, especially flowers, is a mixture of the three called loam. From silt, it derives its ability to retain moisture. Sand creates gaps in the soil that allow plant roots to spread easily. The small particles of clay make it harder for things like nutrients to filter through the soil to where they are not beneficial to plants. Loam is generally considered the best soil for growing things.

But that also depends on the plant. The first step to preparing garden soil is knowing what you want to grow. If you want to grow one or two specific flowering plants, research what conditions those plants like best. Most flowering plants grow best in loam with a medium ph level.

Some plants evolved in an environment that favored slightly different conditions, however. Some plants like slightly sandier conditions, especially if they spread via underground runners. Some plants, especially those that grow in the desert Southwest, prefer slightly more alkaline conditions. This will also help you to avoid placing plants that prefer different conditions next to each other. They might look good on paper, but in reality, one won’t like the growing conditions and it will show.

Now that you know what you want to grow, figure out what kind of soil you have in your yard and what it needs. A quick, simple test is to grab a handful of it and squeeze it. Clay will ooze out between your fingers but will retain the ball shape after you let go. If you poke it, with either a finger or a stick, you’ll make an indentation. Loam, or silt, will retain its shape until you poke it. Then it will fall apart. Sand will fall apart immediately.

If you have clay or sand, you will probably want to add some gardening soil. Gardening soil is basic loam, with some extra bits of bulk compost for an added nutrient boost. Take care to not purchase potting soil, which is specifically designed to retain water when used in pots and other containers. The two are different things.

Next, you’ll want to test your soil. Ideally, you’d do this in the early spring before you prepare it for planting. That way, you can add any necessary amendments as you work the soil.

While there are test kits available at most garden centers or online retailers, if you’re just getting started it’s probably a better idea to contact your local Extension office for a test. Depending on where you live, these are available either for free or for a nominal fee. Either way, it’s worth the small investment because Extension staff will talk you through the results based on what you want to grow. They will also help you map out a fertilizing schedule.

A few words about the kinds of things they’ll explain. The first is the basic nutrient load in your soil. The three main macronutrients are nitrogen, phosphorus, and potassium. On a bag of fertilizer, these are represented by their letters on the atomic chart, NPK.

In general, plants use nitrogen for foliage and potassium for flowers and fruits. Phosphorus helps plants maintain vigorous internal processes. In discussing your soil test results with you, the people with the Extension should also discuss the secondary nutrients.

When it comes to purchasing fertilizers, there are two basic kinds. Chemical fertilizers and organic fertilizers.

Chemical fertilizers, a direct application of the chemical, work quickly because they dissolve quickly. Too much nitrogen can damage the plants. If you go with chemical fertilizer, exercise great care in how much you use.

Organic fertilizers break down slowly, providing a boost that plays out over months rather than weeks. Unless you need the immediate jolt of chemical fertilizer, organic fertilizers are usually much safer because of how long it takes them to break down and add nutrients.

The Extension staff will also talk to you about the ph level of your soil. Not only will ph-levels too high or low kill plants, but a ph outside of certain ranges will also lock up nutrients in the soil and make them unavailable. A rough, basic approach is that optimum nutrient availability is around 6.0, with most plants favoring conditions of between 6.0-7.0, especially in the upper half of that range.

If your ph is too low — too acidic — you may be advised to add some limestone to your soil to raise the ph. If it’s too high — too base — you may be advised to add some sulfur. 

If you want to get your own soil tester to perform these tests more often and keep your soil in the best possible shape, we talked about soil testers in our list of the best gardening gadgets. You can check that out right here.

Once you’ve had your soil tested and have your fertilizing plan set and know whether you need to add anything before planting, you can start preparing your soil. You can start doing this right after the last snows of winter melt away.

The first step is to clean off your soil by getting rid of surface debris like leaves and dead plants. If you have a compost bin, this stuff can go into it for a great post-season addition.

After the beds are cleaned off, add about an inch of compost. Compost has nutrients, but it isn’t the same thing as fertilizer. Fertilizer is the direct application of nutrients. The purpose of compost isn’t to add nutrients to your soil, but to add organic material to it.

This has a couple of significant benefits. The first is that it helps to build your soil system. Soil is the medium in which you grow your plants, but it’s also home to lots of other little critters and fungi. A healthy soil community will enrich your plants and help them thrive. Compost helps build that community.

It also keeps the soil loose. Loose soil promotes the growth of plant roots, which also makes for healthier plants and better flower blooms. The compost will break down over a season, reducing its effectiveness. So, as long as you don’t overdo it, you can add it all along.

In the spring, add composts processed from animal manure, especially from cattle. Be careful about adding fresh manure, especially from chickens. It is so loaded with nitrogen that it can cause the same kind of root damage that adding too much chemical fertilizer can. In the fall, compost made from coarse materials like chopped-up sticks, leaves, and grass clippings is a great late amendment that will slowly break down over winter, adding organic material.

Based on the nutrient roadmap you worked out after getting your soil tested, this would be the time to add any fertilizers or amendments to raise or lower the ph of your soil. Just spread them on the top.

How you mix your compost and fertilizer depends on whether you till. Plants don’t grow well in compacted soil for the same reason they don’t grow well in straight clay. There is no room for their roots to spread. 

Tilling is the fastest, most efficient way to break up the soil, but it’s not always a good idea. It permits soil loss, and if you’ve got good fertile soil it’s a gardener’s most valuable commodity. It also disrupts those underground communities that create an environment in which plants can more naturally thrive.

Tilling your first year is probably a good idea. This will also mix in the compost and fertilizers and get them from the surface to inside the soil.

Be careful to not till when the soil is still wet from the winter thaw. Tilling wet soil causes it to clump together. When that clumped soil dries, it becomes hard and compacted. Contrary to what might seem intuitive, the best way to dry your soil is not to till it and expose the wettest parts to the sun. Just let it dry out.

After your first year of tilling, you can probably skip doing it for a few years, especially if you add compost in the fall and spring. If it is a year or two after you tilled, you can rake in your compost or just turn the earth to mix it in there. The critical depth for compost and fertilizer is in the top six inches of the surface.

If you used animal manure directly for compost, wait a week or so for it to release its nitrogen before you plant anything. Young plants are especially vulnerable to growing conditions, and a nitrogen overload in the soil might kill delicate plants.

If you’re growing annuals for color, remember to wait until after the last risk of frost before putting them into the ground. You can cover the plants at night, but most of them need consistent heat during the day and night to thrive. People also forget that plants exist both above and below the ground.

Depending on the strength of your spring sun and the location of your garden, it will take some time for your soil to warm to promote root growth, anyway. You can cheat a bit here by laying some black landscaping cloth over your garden beds to catch sunlight and warm the soil underneath. But, it’s also not a race.

While you’re waiting for the turned, fertilized soil to warm up, figure out your watering strategy. While this is mostly for your plants, how you water matters for your soil, too. If you focus a hose at the base of your plant, it will not only leach away nutrients and decomposed organic materials that help keep the soil loose, it will compact the soil.

Once your soil is turned and warm, it’s ready for your plants. But your work of preparing your soil is not complete. When you worked out your nutrient schedule after your soil test, you were probably told to add fertilizers periodically throughout the summer. You’ll want to stick to that because some plants — especially those that heavily bloom — can use up nutrients quickly.

If you’re gardening flowers, they are probably not being grown in rows like you might for a vegetable garden. So, there is probably no need for you to step on the beds. Foot traffic is the fastest way you’ll compact your soil. Avoid it if you can.

Especially if your flowers are for landscaping, you can spread a layer of mulch on the entire bed. This helps keep weeds out. It also blocks sunlight from warming the soil and causing moisture loss through evaporation. A natural mulch of shredded tree bark will slowly decompose, too, adding organic matter to the soil as it breaks down.

At the end of your growing season, usually after the first few hard frosts, you can add another layer of compost. The best compost used here is comprised of coarser, more fibrous plant materials. Unlike a bagged manure-based compost that you add in the spring, these break down slowly over the cold months.

Over the winter, let your soil be. Once the snow and ice of winter begin to melt, it will already be partially ready for the new season. There is still some work to do to get it ready for the new growing season, but it’s a lot less involved and you’ve got a season of flower gardening under your belt.

As you can see, preparing the soil to grow flowers is an ongoing process. There’s a lot of work up front, even before you put anything into the ground.

It starts with understanding soil, how plants use soil to grow, and what kind of soil you have in your yard. It also requires that you understand the basic nutrients plants need to thrive, the difference between compost and fertilizer, and how best to add each.

The physical work only starts after you’ve done the book work. You’ll need to loosen up the soil to help plants grow and mix in the compost and nutrients. Whether it needs a thorough tilling or something less violent will dictate how you do it.

Your work doesn’t end when the plants are in the ground. How you water and maintain your garden matter when you prepare your soil next year and the year after.

It’s not hard work. It’s consistent. And it’s that consistency that helps that green-thumbed acquaintance of yours make it all look so effortless.

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