Powdery and downy mildews are two common pathogens that impact plant and crop health. Powdery mildew is a fungus that results in distinct white spots on plant leaves and stems. It’s common among many plants and crops including legumes, cucurbits, apples, pears, onions, maple trees, and grapes. It requires low humidity with warm temperatures, making greenhouses a great environment to infect. On the other hand, downy mildew is a fungus-like parasite that is actually more closely related to algae. It also results in spots which are distinct in that they are more angular, and often yellow or gray in color. In grapes, downy mildew spots are yellow and oily-looking. In mint and basil, downy mildew spots are darker brown or black. Downy mildew is most common in spring and fall with cool nights and high humidity, warm days.

With both mildews, they survive by stealing nutrients from plants which can stress, weaken and even kill the plant. They can also make plants vulnerable to other pathogens and insect damage. Similarly, they can spread via insects like aphids, wind, rain, runoff, irrigation, and contact with infected plants.

Downy mildew is a zoospore, making it capable of “swimming” through water to infect one plant to the next. Spots on leaves can grow larger and denser until they even impact photosynthesis. This can lead to defoliation, sunburn, soft rots, plant death, and can affect the level of sugars that develop in fruit and vegetables and therefore their flavor. Both also have unique varieties that affect particular crops, for example the variety of powdery mildew that has infected squash cannot infect grapes. It is important to be aware of plant families though, as mildew that has attacked basil can be transferred to mint.

Despite their differences, their management techniques are similar. Because they need high humidity to proliferate, it’s best to avoid over-watering techniques, avoid fertilization during outbreaks, properly space plants particularly in greenhouses, and prune overcrowded areas particularly for trees and crops like grapes. Since downy mildew can overwinter, it is critical to dispose all infected plants. For cucurbits, there are some mildew-resistant crop strains. For grapes, berries will naturally protect themselves after 2-3 weeks of their development. However, certain fungicides like sterol inhibitors and strobilurins don’t completely kill mildew and others like difenoconazole are phytotoxic to grapes.

For grapes in particular, and any other affected plant or crop, there are environmentally friendly fungicides and algaecides that can contain both powdery and downy mildew. BioSafe PerCarb is a biofungicide based in sodium carbonate peroxyhydrate that should be applied every 7-10 days to field crops or within greenhouses. To maximize treatment efficiency, it is recommended to supplement with a foliar treatment such as Oxidate 2.0. These fungicides work together to provide increased stability, and again can be applied from seed to harvest via spray, soil drench, or pre-plant drip with a 0-hour re-entry interval and 0-day pre-harvest interval. They are also both EPA certified, OMRI approved, and biodegradable.

Whether you are a garden-enthusiast, commercial agriculturist, or somewhere in the middle, when it comes to producing any kind of healthy plant or crop you need to consider the bugs that they will attract. The relationship between “good” bugs, pests, and our plants goes beyond our control as cultivators. It is our job, however, to support this relationship and where appropriate exploit this relationship to the benefit of our produce. Bugs support healthy ecosystems, and we can attract the “good” ones to protect against the pesky ones.

Unlike chemical pesticides, using bugs to control pests protects against bioresistance and bioaccumulation. Even some environmentally-safe insecticides can harm the “good” bugs, particularly pollinators like bees, so it is always important to follow safety instructions. Some “good” bugs include ladybugs, spiders, praying mantis, aphid midges, tachinid flies, and braconid wasps.

They kill common pests such as aphids, whiteflies, spider mites, thrips, cabbage worms, and mosquitoes. Some of the plants that these “good” bugs prefer include dill, clover, amaranth, alfalfa, coriander, parsley, spearmint, yarrow, lemon balm, marigold, zinnias, statice, evening primrose, and dandelion.

Apart from these predatory “good” bugs, pollinators such as birds, bats, bees, butterflies, beetles, and small mammals also play a critical role in healthy ecosystems and productive green spaces. Between 75-95% of all plant need help from pollinators to successfully proliferate (Pollinators Partnership). And even more importantly, these bugs to it for free! Pollinators contribute $217 billion dollars to the global economy (Pollinators Partnership). Farmers in particular should note that dedicating a portion of farm fields to pollinator-preferred plants can increase overall productivity and yield in crops (Pollinators Partnership). To attract pollinators its best to plant their preferred plant in clumps rather than as individual plants. Depending on the pollinator, they can be attracted to various different flower colors, scents, and level of pollen. Some common favorites include aster, marigold, hellebore, and marigold. As a guide, pollinator.org provides detailed lists of pollinator-preferred plants based on climate and insect type.

When choosing which type of plant to attract the “good”, pest-eating bugs or pollinators, consider also their holistic uses. For example, marigold can attract both types of bugs and its pungent smell is a natural deterrent for certain pests and even larger mammals like rabbits and deer. Herbs like dill, coriander and spearmint work similarly, and can of course be used for culinary purposes. Perennials like yarrow, evening primrose, and asters need to be planted only once and their benefits will last throughout the years. Finally, certain flowers like statice, hellebore, and zinnias are popular cut-flowers with the potential to be used to decorate your home or sold to local florists in surplus. There are endless applications for these attractive plants, with great benefits for the environment and your garden or farm.

Mutually beneficial relationships exist all throughout nature, between birds and insects, insects and flowers, flowers and your favorite garden veggies. Many of your garden veggies are also engaged with mycorrhizal fungi, a healthy fungus that transfers nutrients. There are some companion plant celebrities, like mustard that grows in the vineyards of California, or asters and goldenrod that seem to always find each other in a wildflower field. Regardless, there are often deep-rooted causes and impacts of these relationships.

Mustard plants are rich in phosphorus, and when they are tilled under, they provide necessary phosphorus levels for wine grapes that need it. Mustard seeds are also quite hearty, and can survive in dormancy for as much as twenty years (Sonoma County Tourism, 2020). Mustard also happens to have strong root systems, which protects against soil erosion. And lastly, the glucosinolate which makes mustard spicy and odorous protects vineyards against destructive nematodes (Sonoma County Tourism, 2020).

Asters and goldenrod have a completely different relationship. Each flower attracts pollinators, but often very different pollinators, contributing to their mutual proliferation when they accompany each other in a wildflower field. They are also natural deterrents for deer, host significant pest predators like spiders, praying mantis, and assassin bugs, and fight against powdery mildew and fungal and bacterial leaf spot (Trees for the Future, 2020).

For the purpose of your garden or farm, identifying these relationships among different crops and exploiting them is a great way to both uphold a quasi-natural ecosystem and promote crop health, grade, and yield. Intercropping in general naturally protects against pests as they are more likely to be confused by the combination of plants. And, some plants are better than others at being natural pesticides such as alyssum, nasturtium, marigolds, salvia, “spider flower” or cleome, camomile, garlic and herbs (particularly chives, rosemary, and mint). Many of these contain biofumigants like mustard does, naturally occurring smells that deter pests. Others, like cleome and marigolds to some extent, also have fuzzy or spiky textured foliage that pests can’t stand. There are also countless vegetable companions including, but not limited to: lettuce and mint (mint repels lettuce-loving slugs), spinach and peas (peas provide much needed shade for spinach), cabbage and rosemary (rosemary repels the cabbage fly), tomatoes and marigolds (marigolds repel hornworms and nematodes), radishes and cucumber (radishes repel beetles and aphids), and members of the cucurbit family and flowering plants (flowers help pollinate cucurbits) (Trees for the Future, 2020).

Similarly, some plants can stunt another’s growth or even be poisonous. Some can even attract arch enemies, such as tomatoes which attract corn worms and corn which attracts tomato worms (Trees for the Future, 2020). And, on the other end of the spectrum, there are ways to negatively reverse the relationship that two plants have. A study conducted by Florida International University showed that surplus nitrogen and phosphoric fertilizers resulted in less “sharing” between plants and other plants, plants and animals, and plants and bacteria or fungus (FIU, 2015). This went on to negatively impact plant growth, disease, drought, and food security (FIU, 2015). Therefore, it is critical to keep in mind how intercropping can potentially impact crop health for the worse, and how non-organic practices can be detrimental to positive plant relationships.




Some of the most fascinating methods that can be used to protect cultivated lands and managed forests from pests are those that have developed through biological and evolutionary processes. Like all living things, insects have natural enemies from bacteria to toxic plants to other insects. It seems only logical to mobilize these natural enemies as biopesticides for protecting crops, fruit and nut trees, and ornamentals.
Azaguard is a completely natural insecticide that is based in azadirachtin, named from its source the Azadirachta indica or “Neem tree”. This insecticide contains over 100 limonoid compounds. Limonoids, common in citrus trees and the Neem tree, work as an insect growth disruptor deterring egg-laying and as an anti-feedant leading to insect starvation and death. (Limonoids are also responsible for the sour or bitter taste that citrus fruits offer!) The Azaguard insecticide is effective against destructive pests including termites and the particularly invasive southern armyworm. It is also effective against particular insects that are resistant to other commonly used biopesticides such as the Bacillus thuringiensis bacteria. While most effective when applied during the larval stage, it can be applied at any point during larval, pupal, or nymphal stages of insect development. It should be applied at least every 10 days, and is safe for greenhouse or field applications via drop irrigation, soil drench, fogging, or aerial applications. It is immediately effective, has a 0-day pre-harvest interval, and biodegrades in about 4 days after exposure to light or water.
Apart from using limonoids as a weapon, there are even more complex natural processes that won’t only deter insects but actually kill them. BioCeres WP is a mycoinsectide, meaning it is a microbial insecticide that infects insects with a living pathogen that ultimately causes insect death. In this particular case, Beauveria bassiana fungus is spread to insects including whiteflies, aphids, thrips, weevils, and cabbage maggots. Again, this pathogen is a completely natural enemy to the insect, which has been harnessed to control pests in agricultural settings. The BioCeres biological mycoinsecticide works by adhering to the insect’s outer skin, then penetrating their exoskeleton and infecting them with white muscardine disease. The insects then die within a matter of days. The symptoms of this disease are visible on insects, noted by a white foamy coat, although it is also important to note that this pathogenic process can also successfully kill insects before the symptoms are visibly apparent. Unlike other forms of pesticides, it is very unlikely for insects to develop a resistance to mysoinsecticides due to their natural relationship. BioCeres WP can be applied via soil drench or as a foliar spray every 5-7 days. It is effective during all stages of insect development, has a 4-hour re-entry interval and also has a 0-day pre-harvest interval. Both biopesticide solutions are OMRI and EPA approved, with the former also being Kosher. So next time you’re not sure where to turn to claim victory over the insects, look no further than their own natural-born enemies.

Fertilizing is not necessary for some plants, as we have seen. But the station plays a vital role since we do not feed the plants in the same way at all times. Generally, fertilizers should be supplied once every six weeks during the spring and summer seasons. In winter periods, the fertilizer is supplied once every ten weeks.

When to fertilize in spring?

In spring, just before the season begins, fertilization favors the regrowth of the plants. The roots are very active at that time and are ready to receive nutrients. They need, therefore, a fertilizer that puts nutrients at their disposal quite quickly. But not in large quantities, because there is a risk in the case of excess use of fertilizer.

A rich fertilizer, of rapid diffusion, with a well-adjusted dose, is what plants need in poor soils and for “gluttonous” vegetables. If you prioritize it efficiently, you can provide organic fertilizer, with a relatively rapid diffusion, such as those presented in powder form. If not, use liquid organic fertilizers or synthetic fertilizers, which act either immediately (be mindful of overdosing) or slowly. Make Biosafe weed control spray mandatory to be used during the fertilization if you need healthy results for your flora.

When to fertilize in summer?

Summer represents the season when the crops are already developed, even the seasonal ones. If they need to fertilize, it will be with a quick-acting fertilizer. You will find in this category chemical fertilizers and organic fertilizers, such as guano, or potash in granules. They act immediately, and any overdose leads to burning of the roots.

When the summer is extreme, you can start giving slow fertilizers, from which the plants will benefit during the fall and even the following spring. Rapid fertilizers should not be used on plants that are already beginning to decline, because all they would do is contaminate the soil.

When to fertilize in autumn and winter?

The plants enter a resting period, even if they do not lose their leaves or if they bloom during the winter. For this reason, they do not need to be nourished at this time. The star winter fertilizer is, of course, manure. Put a 5 to 15 cm layer on the ground and at the foot of the crops, which will slowly decompose when plants need it.

With manure, you do not risk an overdose. The best time to use it is during January-February. If we apply it before, the nutrients it contains would be released by winter rains. On the other hand, if it is extended later, it will not give you time to decompose for spring (it will nourish the plants during the summer).

Enviro Selects offers fertilizers made from organic raw material. Attention should be paid to know which fertilizer is the most suitable to ensure optimum plant growth.

BioSafe Disease Control ensures the correct growth and maturation of your fruit trees. Discover the products we have for your plantation. Get in touch with us now!

OxiDate and TerraClean are ideal companion products as a preventative disease control solution that kill a wide range of harmful fungi and bacteria, on contact. For foliar applications, OxiDate is recommended for use with both field-grown crops and commercial greenhouses and is OMRI approved for use with organically grown crops. TerraClean is a broad spectrum bactericide/fungicide engineered specifically for water and agricultural soil treatment and is also OMRI approved.

OxiDate 2.0 Broad Spectrum Bactericide/Fungicide

OxiDate 2.0 kills a broad spectrum of harmful fungi and bacteria using state-of-the-art peroxygen technology that rapidly oxidizes on contact, protecting crops from disease-causing pathogens. Oxidate can be used as a pre-plant dip, soil drench, foliar treatment, and surface disinfectant.

Benefits of Oxidate include:

  • Zero Hour Re-entry Interval (4 hrs in California)
  • Zero Days to Harvest (can be applied until harvest)
  • Exempt from Pesticide Residue Regulations
  • No Mutational Resistance
  • OMRI listed for Organic Use
  • Environmental Protection Agency (EPA) Approved (EPA# 70299-2)

TerraClean 5.0 Broad Spectrum Bactericide/Fungicide

TerraClean 5.0 is a broad spectrum bactericide/fungicide engineered specifically for water and agricultural soil treatment. TerraClean can be applied throughout the growing season to control and eradicate many harmful soil pathogens such as Fusarium, Pythium, Rhizoctonia, and Phytophthora. Most effectively applied using drip irrigation systems, TerraClean is designed to penetrate the soil and chemically react to kill pathogens and release large quantities of oxygen into the soil that stimulate root development, nutrient intake, and plant growth.

TerraClean has many benefits, including:

  • Zero Hour re-entry interval (REI)
  • OMRI listed for Organic Use
  • Simple application through drip irrigation for effective control of soil pathogens
  • Can be applied at all stages of the growing season, including planting
  • Increases nutrient uptake by enhancing oxygenation of the root system
  • EPA approved (EPA# 70299-5)