How to fertilize your garden, trees in summer

How to fertilize your garden, trees in summer

For some crops, midsummer fertilizing can present a needed enhance soon after a few months or much more of vigorous increasing. But for numerous many others, fertilizer can be unnecessary or even dangerous.

“Only fertilize vegetation if you are absolutely sure they need to have it,” claimed Julie Janoski, manager of the Plant Clinic at The Morton Arboretum in Lisle. “Applying fertilizer when it isn’t required or at the incorrect time, or applying much too a great deal, can dry out plants’ roots or make chemical imbalances.

“If you around-fertilize crops, you could get too many leaves at the expenditure of bouquets,” she reported. Surplus fertilizer also finds its way into rivers and lakes and results in severe air pollution difficulties.

Trees and shrubs seldom need to have fertilizer. “We don’t usually propose fertilizing them unless of course a soil test has revealed a specific nutrient deficiency,” she stated.

Most perennials really do not will need fertilizer both, as very long as they are planted in soil that has satisfactory natural and organic issue. Organisms in healthful soil will digest the organic make a difference to deliver the nutrients the perennials require.

Which plants do have to have fertilizing? “It’s typically plants these kinds of as flowering annuals that are expanding in unnatural situation, this sort of as containers, exactly where they can’t accessibility nutrition from a wide region of soil,” she claimed. “In those conditions, they quickly use up the accessible vitamins, and they can use some more help.” A fertilizer boost can also enable veggies maintain generating via the harvest season.

Fertilizer is not plant foodstuff. Vegetation make their have foods by means of a chemical method called photosynthesis that captures energy from daylight. Fertilizer can dietary supplement plants’ meals with an increase in certain chemical features they have to have to develop significant molecules.

In nature, plants get all the things they require from the soil. In our house landscapes, which are generally pretty distinct from plants’ pure residences, particular plants may possibly create deficiencies that fertilizer can offer. For illustration, if a pin oak tree is planted in alkaline soil somewhat than in the acidic soil this tree species prefers, it could develop an iron deficiency that can be helped by fertilizer. A bur oak tree, which is adapted for alkaline soil, would not want it.

Below are some tips from Janoski for summer fertilizing:

Use slow-release. Fertilizer formulation that dissolve little by little into the soil will release nutrients steadily and stay away from overdosing crops. Natural and organic fertilizers are all gradual-launch, as are some synthetic formulas.

Examine the ratio. The label of each fertilizer item has a ratio, this kind of as 3-1-1, indicating the percentages it is made up of of nitrogen, phosphorus and potassium, the aspects that plants use in the most significant quantities. “Look for figures in the reduced one digits, which suggest that the item is a gradual-release method,” Janoski explained.

Much more is not much better. Under no circumstances exceed the quantities advised in the instructions. “Err on the side of using a lot less,” she explained. “If you’re using a liquid fertilizer that is dissolved in h2o, you can engage in it secure by making use of half the total recommended on the label.”

H2o to start with. The substances in fertilizer are fundamentally salts and can easily dry out plant tissue. For insurance policies, make absolutely sure the crops are properly supplied with drinking water before you fertilize.

Use at the suitable time. Distinctive plants may well need supplemental nutrition at different times. Fertilizing in summertime can enable once-a-year flowers retain blooming till frost and maintain veggies making. Lawns, even though, are most effective fertilized in early slide, when they have begun developing once again in cooler weather, and the fertilizer can help them increase solid roots. In the exceptional situations that trees or shrubs need to have fertilizer, it is greatest applied in spring or slide. Talk to the Plant Clinic for information on regardless of whether and when to fertilize distinct plants.

Fertilizer is not a heal-all. “The only detail fertilizer can aid with is a scarcity of individual vitamins,” Janoski explained. “If that is not the trigger of the challenge, fertilizer will be worthless.” Usually detect the rationale that a plant is not increasing effectively just before you make your mind up no matter if fertilizer could possibly be helpful.

Take a look at your soil. “A soil check can tell you the chemical composition of your soil, to enable you opt for vegetation that are likely to grow effectively without having the will need for fertilizer,” she claimed. Master more at

For tree and plant suggestions, call the Plant Clinic at The Morton Arboretum (630-719-2424,, or [email protected]). Beth Botts is a personnel author at the Arboretum.