Best Cover Crops For Your Garden

Cover Crops

Cover crops do more than help with soil erosion and weed control. They also help to put nutrients and organic matter back into the soil as well as help with weed and pest control.

The best cover crops for winter gardening are those that add nitrogen and nutrients to the soil. These include cereal grains like oats, barley, and rye.

Growing a cover crop in your garden will improve the soil by adding organic matter to the soil which decomposes, but the organic matter can also feed earthworms.

Their casting has higher levels of nitrogen, nutrients, and a neutral pH level, as well as beneficial microbes that help plants to fight diseases.

Cover crops can also be used in containers or raised garden beds. A diverse cover crop is essential to the never-ending task of soil management.

Remember that each type of crop has a purpose. Legumes fix nitrogen to the soil, grasses aerate the soil, and brassicas plants prevent pathogens and improve the structure of the soil.

To keep your soil in the best possible condition you can plant a cover crop after you have harvested the main crop.

Depending on the main crops being grown at the time, some cover crops can be planted to speed up the improvement of the soil.


Cover crops that contain legumes fix nitrogen and improve the soil. A chemical reaction happens because of the Rhizobia bacteria in the nodules of the roots.

For this process to take place, the legumes must have a healthy root system and be well-established to fix nitrogen in the soil which takes several weeks to happen.

Seedlings tend to use more nitrogen than they fix in the soil, therefore it is recommended to start the seedlings indoors and transplant them after three to four weeks.

Soil bacteria and legumes work together to convert atmospheric nitrogen into ammonium and the plants then use the nitrogen to produce proteins.


  • Hairy Vetch
  • Austrian winter pea – also known as field peas.
  • Blackeye peas – also known as cowpeas.
  • Red Clover
  • Crimson Clover


  • Aphids
  • Thrips
  • Leafhoppers
  • Whiteflies
  • Mexican bean beetles


  • Powdery mildew
  • Downy mildew
  • Botrytis grey mold
  • Ascochyta blight
  • Anthracnoses


Growing cereal grains can significantly improve soil aeration as well as water retention.

When the soil becomes too compacted it will make it harder for seedlings to establish a good root structure.

A soil compaction test can be done by digging a hole and looking at the soil, if you see layers, then your soil is too compacted.

These grains have a high aeration rate due to their wide roots and low starch content. These types of grains are ideal for any home gardener and should be a part of any cover crop.

This is because they can grow in a variety of soil types, they can tolerate light frosts, and their roots and stalks are high in carbon and are turned back into the soil in the spring.


  • Oats
  • Barley
  • Winter rye – the hardiest grain for growing in winter.
  • Winter wheat
  • Triticale


  • Rice weevil
  • Granary weevil
  • Rust red flour beetle
  • Lesser grain borer


  • Stagonospora nodorum blotch
  • Septoria tritici blotch
  • Tan spot
  • Powdery mildew
  • Leaf rust
  • Crown rust
  • Septoria blight
  • Leaf blotch
  • Net blotch
  • Scald
  • Foliar diseases
  • Yellow dwarf
  • Fusarium root
  • Crown rot


Buckwheat is a fast-growing, short-season cover crop that can grow to maturity within 70 to 90 days.

This cover crop is often used in the summertime during times when crops are not planted, known as fallow.

In the summertime, it will help to control weeds while attracting pollinators to your garden when its blossoms are blooming.

It also loosens the top soil which helps water get to the roots and improves low-quality soil.

In 6 to 8 weeks buckwheat will produce 2 to 3 tons of dried plant matter per acre and it decomposes quickly.

It doesn’t overwinter but when turned into the soil and decays, it increases the nitrogen levels in the soil and helps to hold in moisture.


  • Aphids
  • Cutworms
  • Deer
  • Turkey


  • Damping-off – also known as root rot
  • Powdery mildew
  • Stem rot


Alfalfa is a great cover crop that fixes nitrogen to the soil and nutrients to it as well. It also prevents soil erosion and loosens the soil below the upper surface without turning the soil over.

Their roots grow 9 to 16 feet deep creating channels for water to get deep into the ground which makes for great compost in your garden soil.

The roots of alfalfa create natural chemicals that make the best environment for microorganisms around the root system.

These microorganisms in turn improve the soil making for an optimal growing medium for the next year.

Alternatively, alfalfa pellets can be purchased, soaked overnight, and added to your garden or compost pile. It will decompose quickly as a plant or as pellets.


  • Alfalfa weevil
  • Alfalfa caterpillar
  • Aphids
  • Cutworm
  • Grasshopper
  • Cucumber beetle
  • Blister beetle
  • Armyworm
  • Slug


  • Stemphylium leaf spot
  • Stagonospora leaf spot
  • Spring blackstem
  • Downy mildew
  • Damping off
  • Common leaf spot
  • Bacterial wilt
  • Fusarium wilt
  • Verticillium wilt
  • Anthracnose crown rot


With over 4,000 species in this family of nutrient-rich plants, they contain glucosinolates that interfere with the life cycle of fungi and nematodes when tilled into the soil.

Within this family of plants are radishes which work great to break up compacted soil and provide phosphorus and potassium when they are left in the soil to decompose.


  • Mustard
  • Cabbage
  • Napa Cabbage
  • Kale
  • Broccoli
  • Cauliflower
  • Radish
  • Turnip
  • Watercrest
  • Wasabi
  • Arugula
  • Collards
  • Rapeseed


The seeds can be scattered over the garden to provide enough ground cover and weed control.

Arugula produces a large amount of biomass that helps to keep the weeds down

It can also be used as a companion plant with asparagus for example to keep weeds down.


  • Flea beetle
  • Cabbage worms
  • Nematodes


  • Downy mildew
  • Bacterial leaf spot
  • Damping off


Mustard prefers cool weather, quickly germinates, has a 1 to 3 feet deep tap root, matures in 80 to 95 days, and produces a lot of biomass that helps to control weeds.

Legumes can be added in with mustard greens to fix nitrogen in the soil in order to improve the condition of the soil.

Mustard needs to mowed and tilled into the soil before or at flowering, but it should not be allowed to go to seed because it will become a hassle.

They have high amounts of glucosinolates when composted which help to keep pests such as bacteria, fungi, and nematodes as well as weed control.


  • Green wave mustard
  • Kodiak mustard
  • Florida broadleaf mustard
  • Osaka purple mustard – has a broader leaf than a purple wave.
  • Purple wave mustard
  • Red giant mustard
  • Red tatsoi mustard
  • Rosette tatsoi mustard
  • Mizuna mustard
  • Tendergreen mustard – also known as Japanese mustard spinach is ready for harvest in 35 – 40 days.


  • Nematodes


  • Bacterial soft rot
  • Bacterial black rot
  • Xanthomonas leaf spot
  • Alternaria black spot
  • Damping off
  • Downy mildew
  • Powdery mildew
  • Leaf spot
  • White leaf spot
  • Southern blight


Oilseed radishes contain glucosinolates which reduce the number of plant-parasitic nematodes, bacteria, and fungi as well as helps to control weeds.

They should be planted 6 to 8 weeks before temperatures fall below freezing to ensure that they will make it through the winter. They can be started indoors, using cardboard seed starters.

Unlike other cover crops, oilseed radish has an extensive root system with highly decomposable roots that are high in phosphorus and potassium.

It produces large amounts of biomass and recycles excess nutrients in the soil. The plant’s low carbon-to-nitrogen ratio helps prevent water quality issues by storing nutrients in the soil.

Radishes also smother weeds and provide a quick cover crop that can produce tons of dry biomass per acre.


  • Oilseed Radish
  • Daikon Radish
  • Spanish black radish
  • Watermelon radish


  • Aphids
  • Cutworms
  • Flea beetles
  • Cabbage loopers
  • Harlequin bugs


  • Alternaria blight
  • Downy mildew
  • Fusarium wilt
  • White rust
  • Damping off


Turnips are often used by cattle farmers to feed the cattle with greens during the winter months and the roots keep the soil from becoming too compacted.

They store nutrients in their roots while keeping weeds down and they produce a lot of biomass when they are mature.


  • Royal crown
  • Top star
  • Scarlet queen
  • Sweet scarlet ball
  • Golden ball
  • Gilfeather
  • White lady
  • Snowball
  • White egg
  • Nozawana


  • Aphids
  • Root maggot
  • Slug
  • Snail
  • Diamondback moth


  • Black rot
  • Bacterial leaf spot
  • Downy mildew
  • White rust
  • White mold
  • White spot
  • Alternaria leaf spot
  • Anthracnose
  • Clubroot
  • Turnip Mosaic

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Joel Simon

As a kid, Joel found enjoyment in caring for the many houseplants he grew up with, learning how to transplant them safely, cloning them, and more. At about the age of 10, he wanted to see if he could sprout an orange seed from a store-bought orange and ended up using it as a science experiment in a school project. Throughout the many years of gardening, he has helped many friends and family set up their food and botanical gardens. After years of caring for plants, he was talking with other gardeners and discovering old methods of farming and botanical gardening. Joel has decided to share his knowledge for others to enjoy as he has for many years.

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