Priming, Prepping, and Maintaining Your New Soil

por Ben Dickerson 22 de enero de 2022

“A poor farmer grows weeds, a mediocre farmer grows crops, and a good farmer grows soil.” – Unknown, maybe Japanese Proverb.

Raise garden bed with scallions and herbs.

Think of soil building the same way athletes approach fitness. You can’t buy the ability to run fast or far, but you can buy products to help you along as you develop that ability. Success is a combination of time, effort, planning, and maintaining. Just like you can’t go for a jog today and wake up tomorrow running like Usain Bolt, purchasing soil and filling a raised bed won’t give you a garden like Elaine Ingham. And just like there is no one-size-fits-all plan to fitness, there is no perfect pre-scribed plan to a successful garden. But there are foundations of knowledge to utilize to coach the plan along.

Priming and Prepping the Soil

You may have heard the term ‘prime’ once or twice through your gardening adventures, but what does it mean? Priming soil is akin to athletes ‘carb-loading’ before a big event. Just like athletes need a good amount of sugars and protein to convert to energy, soil needs a good amount of organic matter to convert sugars and proteins into base nutrients for plants. Technically- priming the soil refers to the process of adding new soil carbon to soil which in turn increases the decomposition of old soil carbon. If you’re a science nerd like the team at Soilutions, you can read a great study on global soil priming here. Adding compost at the beginning or end of a growing cycle or adding it to a mix of inert media like coco coir or peat moss, is the priming process.

When you hear the term 'priming' in less scientific circles it is commonly used interchangeably with preparing- climatizing, watering, cover cropping, etc. Almost all “complete” soils or potting soils you buy in a bag are primed, but that doesn’t mean they are ready to grow the perfect plant straight out of the bag or dump truck. You can’t just grab a protein shake and run a marathon with no preparation. Likewise, you can’t grab a bag of soil and grow the perfect garden. Each time you start with a new soil, whether in a 5-gallon pot or 5-acre field, you need to evaluate the soil conditions and prepare it to support vegetative life. Preparing the soil properly will save you time and effort trying to fix problems that may arise during the growing season. We recommend the following steps with all new soils.

Amending. If you buy a bagged potting soil, chances are you are buying a soil-less media comprised mostly of peat moss or coco coir and perlite. If you grow hydroponically or with non-organic fertilizers and only plan on using the potting soil once, these mediums are just fine, but you will need to fertilize throughout the season. Most non-flowering houseplants will survive, if not thrive, in these soils with little to no maintenance other than watering. If you plan on re-using this soil for fruits, vegetables, or flowers you should always add minerals to these soils. Basalt dust, pumice, cinder, granite, and even coarse sand all contain silica and other minerals and micronutrients that are vital for long term soil health. Some products, like Soilutions soil blends, are intended for long-term use and are blended with a composition of minerals along with organic matter.

Environmental Stability. Just like athletes perform better when they are comfortable with the environment, soil performs better when it’s adjusted to its surroundings. Move the soil to its final home and keep the soil in the conditions you’ll be growing in for a few days or even weeks. This will allow the soil and microbial life to achieve stability with the temperature and humidity of the growing area while also giving you time to understand the moisture needs of your soil. Of course, conditions in outdoor gardens will need to be reassessed regularly to adjust for seasonal changes. Unless you are growing cold weather crops, soil temperature should be at a minimum 65°F for seeds and transplants.

Water thoroughly. All organic soils will contain decomposed organic matter (compost) in one form or another. Soil microbes are just like all life- they need water, food, and oxygen to thrive. You should always water new purchased soils or freshly primed gardens to drain out the salts that acquire in both the existing soil. This can be tricky- you don’t want to overwater and lose all the nutrients, and many soils tend to become “hydrophobic” or resistant to excepting moisture. Water slowly until fully saturated, then water a little more to runoff excessive salts. There is no perfect calculation, but you do want a little runoff. Watering new soil around the far perimeter of native tree root systems is a good way to prevent wasted water. Allow the soil to dry to the level of a damp sponge- dripping but not pouring when you squeeze it.

Some crops require more nitrogen, some require very little. You don’t necessarily need to know the values of nutrients or be a greenhouse chemist to properly fertilize but understanding what comes in your purchased soil and what your plants need to thrive is important. Some soils will list the guaranteed analysis in the N-P-K format, but this can be confusing as they are only required to list the minimums. Nutrient cycling in organic soils can cause measurable values to change from day to day, so some soils will have much greater N-P-K values than listed so they ensure the absolute minimum listed on the label is met. Plants also require different nutrient levels at different phases of life- so spend some time with botany books and blogs to familiarize yourself if you’re interested in specific plants, but for most backyard gardens an all-purpose fertilizer should cover all your crops needs.

Cover crops and living mulch. Adding nitrogen fixing cover crops like clover, sweet peas, hairy vetch, and many legume varieties will help keep the nutrient cycle active through all soil layers, and over time will help lower the dependence on nitrogen fertilizers. In both potted plants and gardens creeping thyme and other ground loving cover crops can act as a “living mulch” that protects the top layer of soil from drying out. We recommend lightly seeding cover crops after the initial amending, watering, and fertilizing, but before you sow your crop seeds or transplant. Be careful to not overplant in confined spaces.

Maintenance

Now that your soil is ready for growth, it’s time to seed or transplant. Sowing directly in freshly mixed soil can present problems- seeds come with their own food storage system built in, so young plants have all they need to survive in inert media. A rich soil can cause nutrient burn or stunting to young seedlings. Regenerative soil systems take time, but that doesn’t mean you can’t or won’t have success immediately. Remember- old, rich, verdant forests are the result of millions of years of soil development. First year maintenance with new soil may come with some learning curves.

When using organic nutrients or fertilizers you’ll often hear that you can’t overfeed- the soil processes and makes nutrients available when plants need them. This is like saying there’s no such thing as too many protein shakes. An extraneous amount of anything can create problems. This may be true to an extent, but a balanced approach with a back-up plan is the best option. We designed our Soil Food All-Purpose Nutrient Blend to be a monthly maintenance fertilizer.

Monthly applications of worm castings and compost tea can keep the microbial levels high as well. A well-maintained soil may still run into problems, so we always recommend having water soluble organic fertilizers available to quickly fix deficiencies. As the regenerative process develops over time, you’ll likely need less and less fertilizer to maintain a healthy garden, with only compost and sometimes a few minor mineral applications like rock phosphate.

Hydration is the single most important factor in success. Watering correctly is the most common difficulty high desert gardeners and farmers face. In New Mexico, evaporation can account for up to 70% of soil moisture loss, so it’s important to protect the soil with mulch. Mulch protects the surface of the soil, helps keep the soil temperature regulates, and prevents evaporative moisture loss. Ideally the moisture levels in the soil stay consistent to reduce stress on the plants. Inducing stress can be a beneficial practice, but it’s a learned skill that takes experience to master. However, most gardens will experience water stress, either too little or too much, throughout the growing season.

If your garden or container is too dry, don’t try to make up for it by drowning your plants. Water travels through soil via gravity, so add water in short intervals throughout the day to prevent water from oversaturating the lower root zone. If you overwater in raised beds or in-ground, there isn’t much you can do but wait it out. If plants don’t show signs of recovery as the soil dries out, you can apply an organic fungicide and a little extra nitrogen fertilizer to combat the effects of root rot. In potted plants you have more options such as repotting the plant and increasing airflow through the root zone.

Finally, regular applications of compost, either the beginning or end of the growing cycle, will keep the soil happy and thriving. Adding compost in the fall or at the end of a growing cycle is ideal, but you can add compost at any time. You do want to make sure that you don’t plant for a few weeks after adding large amounts of compost, you’ll want the soil to adapt to the influx of organic matter. Small amounts of compost or worm castings can be added as a top or side-dressing throughout the growing season without concern.

The final element necessary for a successful garden is patience. Athletes don’t magically reach their peak fitness overnight, and even the most fit athlete suffers minor setbacks. Athletes pay attention to their bodies and get to know when discomfort is a problem or something they can push through. This is a learned skill. New gardens, especially in conditions as difficult as New Mexico, can be difficult to manage. Spend time looking at each plant, feeling the soil, and keep a notebook of what plantings are successful and what struggle and what the difference is. All it takes is one shade tree create two very different sets of growing conditions, so pay attention to details that may seem insignificant. You can’t talk to the soil, but you can listen to the plants.