Sunday, June 30, 2013

Fertilizing the Garden


Whether you grow organically, conventionally or whatever-you-have-available-ly, making sure your plants have enough nutrients is an important part of good gardening. If your soil already has a normal pH, a healthy amount of organic material and available nutrients you may be fine, but if it doesn’t you may need to add additional fertilizer and nutrients to your plants. (If unsure you can check the mineral composition by having your soil tested through a soil testing facility near you). Whether you choose to improve soil nutrients by compost, green manure, or synthetic fertilizers, the choice is up to you.

Knowing what is in your fertilizer, and what your plants need is the first step in proper fertilization. Plants require both macro and micronutrients, and the composition and amount of these nutrients change depending on what growth stage your plants are at. The three macro elements plants require are Nitrogen (N), Phosphorous (P) and Potassium (K). Micronutrients and the amount needed, vary for particular plants, but boron, manganese, sulfur and calcium are all common ones. While these may not be as well known as the macronutrients, they too play an important role in your plant’s health. Even if macronutrients are abundant, plants can only be as successful as the least available nutrient.

Peas happily growing in the garden. These likely don't need fertilizer.
Commercial fertilizers typically have three numbers (i.e. 20-10-5). The first number refers to the nitrogen content, the second to your phosphorous and the third to the amount of potassium. You can buy complete fertilizers (with some combination of all three nutrients) or you can buy single element fertilizers (pure phosphorous fertilizer would be 0-10-0). Nitrogen is a major component of your garden plants and is essential for plant growth. In many fertilizers it is going to be the bulk of the nutrients. Using a granular application of nitrogen before planting can supply sufficient nitrogen for the entire growing season. Nitrogen will boost your foliage growth, increasing plant size and photosynthesis. Nitrogen sounds amazing for your plants, right? Well too much of a good thing can also be a problem. Too much nitrogen can leach through the soil and contaminate ground water and it can reduce flowering, which will decrease your yields in many instances.

Phosphorous (the second number) is important for energy production, protein synthesis and plant growth. Potassium (the third number) is important for many plant processes including response to drought, insects. Early during the growing season when the soil is cooler, it is more difficult for plants to take up phosphorous (and potassium). As the weather warms, these minerals will become more available and fertilization may not be necessary (depending on your natural soil levels).
For best yields, cucumbers need additional nutrients
In general, you should apply fertilizer early in the growing season to promote vigorous plant growth, applying a fresh mixture almost monthly Remember, fertilizing won’t improve your soil’s structure, microbial community, or drainage, but if properly implemented can improve your plants’ health and yields. So even though rain may be abundant, don’t forget to add a to add some extra nutrients to your plants. They’ll love you for it.

Sources consulted:
Utah State University Bulletin on successful fertilizing:

From the Missouri Master Gardener’s manual: http://extension.missouri.edu/p/MG4

Oregon State University manual:

Penn State Guide on Fertilizers:

Wang M., Zheng O., Shen O., Guo S. The critical role of potassium in plant stress response. 2013. Int. J. Mol. Sci. 14(4) 7370-7390.

Saturday, June 15, 2013

National Pollinator week: Bee-palooza

What do birds, wasps, bees, flies and some mammals have in common? They can all be pollinators!
Syrphid fly on a flower (syrphids mimic bees at a first glance, but look more closely and you'll see it's actually a fly).
Pollinators are an essential part of any gardening environment and six years ago the U.S. Senate designated a week in June to be National Pollinator week. This year, that week is June 17-23, 2013. To celebrate the occasion, Michigan State University is hosting its 2nd annual Bee-palooza on campus Sunday (June 23rd) from 1-4pm at the Horticultural Demonstration gardens. If you're in the area definitely stop by and check out this free event featuring pollinators. If you aren't in the area, go online and see what is happening in your own neighborhood.

A version of a solitary bee hotel (at MSU).
There will be MSU entomologists (scientists who study insects) talking about native plants, attracting pollinators (native bees and other insects), building nesting boxes for solitary bees, bee-friendly garden designs and there will be plenty of activities for children as well. If you want more information here is their Facebook page for the event. (Note: In the event of rain it will be canceled.) They will also have a live bumblebee hive on display and stinger-less males for people to touch.

Bumblebee on a flower.
Whether you want to build your own bee hotel, add bee friendly plants or just enjoy the MSU gardens, this event is sure to be fun and educational.

I hope to see you there!

If you want to know more about national pollinator week and ways to celebrate here are a couple of sites:
http://pollinator.org/pollinator_week_2013.htm

http://www.wildlifehc.org/ideas-for-celebrating-national-pollinator-week/

Wednesday, June 5, 2013

Weeds in the garden

 
Sorry for the delay in this post, but when the sun is shining and the garden is calling it’s hard to sit in front of a computer. Over the next couple of weeks we’ll be covering basic garden care and we’ll start talking about insects. We’ll also be starting to feature great gardens around the Greater Lansing areas. If you (or someone you know) has a garden you’d like featured send me a message.


Gardening season is off and running, but for many of us gardening is our hobby or side activity. Life, work and other things can quickly fill the time that you’d like to put into your garden. While there are some times of the year that your garden can handle neglect, early in the spring is not one of them.

Weeds
Those tiny seemingly innocuous weeds you see popping up might not seem like they are hurting your transplants and seedlings, but looks can be deceiving. Besides being an eyesore, weeds can cause lasting damage or setbacks to your transplants and seedlings especially if allowed to stay for a couple of weeks. A lot of research has been done on weed management, but in general weeds should be removed as soon as possible and definitely before they have reached the four to six leaf stage. This means that weeds should be pulled before they have four real leaves.  For some vegetables (like leeks) weed control should be started as soon as seven days after transplanting! A study on cabbage, cucumbers and tomatoes found that plots needed to be kept weed free for 3-4 weeks after transplanting or yields were reduced. In snap beans yields were reduced by almost 50% when weeds (emerged at the same time as the beans) were not controlled. Weeds don’t only reduce yields by stealing nutrients and shading out those transplants. Sometimes, they can also be hiding disease-causing organisms.
This lambsquarter has four true leaves and should be pulled.
 
Weeds can also harbor pathogens. Sometimes a plant can be infected with a pathogen, but it won’t show any symptoms. There won’t be any leaf spots, yellowing, rot etc. Depending on what it is, that pathogen can then infect and cause disease (with symptoms) on your vegetables. Did you know that nightshade, horse nettle and jimson weed are in the same family as your tomatoes, eggplants and peppers? And lambsquarter and pigweed are in the same family as beets and swiss chard. Just like you need to rotate crops to reduce disease pressure, you also need to manage weeds, especially those in the same family. A number of diseases are believed to survive on weeds including powdery mildew, downy mildew, and some leafspots and viruses.

These weeds are small now, but can quickly overtake a young bean plant

So make sure to find the time this spring to get out there and remove those weeds before they get to be a real problem! And I’ll be doing the same. 

Some sources on weeds:
http://extension.missouri.edu/p/IPM1023-45

Turson, N. et. al. 2007.  Critical period for weed control in leek (Allium porrum L.) http://hortsci.ashspublications.org/content/42/1/106.full.pdf

Weaver, S. 1984. Critical period of weed competition in three vegetable crops in relation to management practices.  DOI: 10.1111/j.1365-3180.1984.tb00593.x

Groves, R. et al. 1995. Association of Frankliniella-fusca and 3 winter weeds with tomato spotted wilt virus in Louisiana.

Aguyoh, J. and Masiunas J. 2003. Interference of redroot pigweed (Amaranthus retroflexus) with snap beans.