Just the other day, a customer was in our greenhouse and commented how beautiful our fall pansy crop looked. He then asked how long I had been working at Kube Pak. I told him I had just passed my 20th year as head grower and, in all those years, there has never been a dull moment.
The final and most intriguing question he asked was this: What do you owe your success to as far as growing beautiful crops year after year? My answer was pretty simple. I told him that when you’re growing crops you want repeated year after year, always go back to the basics. But what is meant by going back to the basics?
If you look at growing from a simplistic point of view, it’s an easy job. You take a seed or a plug and put it in a flat or a pot, making sure you place it in a greenhouse, of course, and off it grows. So why do so many growers struggle at growing certain crops year after year? The old-school mentality used to be “just feed it,” and it worked half the time. But with the economy the way it is, no one can afford any loss because all of our margins have shrunk.
So what can you do when you see something go awry in a crop? The answers come from basic processes many growers forget. As growers, at some time or another we are posed with the question: What is going wrong? Here are some processes you should go through to diagnose problems.
Let’s use an example of a grower or plug customer who is having problems with vinca. Always begin with the lifeline of plants: the soil. The checklist should look like this:
1. Are you using the same mix as last year?
2. What is the current pH of your soil? I say “current” because many growers refer to the original starting pH of their mix. Vinca likes a pH of around 5.8.
3. Air porosity and soil compactness are important considerations some growers forget. You can have a very good soil makeup, but if the production people pack the soil too tightly, you lose all the characteristics you thought you were getting, leading to poor root growth and plant development.
Water is a key input, too. You might be surprised how many operations don’t know the pH and alkalinity of the water coming out of their hose. At Kube Pak, our water has a pH of 6.4 and the alkalinity is 75.
Why is knowing this so important? Before you can figure out what type of fertilizer to use, you need to understand what your water is doing to the pH of your soil. Once you go over an alkalinity of 150, your soil pH will begin to creep up so you will have to inject acid to lower the alkalinity and/or use an acidic fertilizer to help maintain a proper pH.
Too low a pH can cause minor nutrient toxicity on many crops; too high a pH can cause deficiency in elements like iron and boron. Many growers can avoid nutritional problems if they check their water.
What type of fertilizer are you using? Fertilizers have changed for the better in the last 10 years to enhance plant development. Many years ago, the most popular fertilizer was 20-20-20, in which you get 20 parts nitrogen, 20 parts phosphorous and 20 parts potassium. That feed has 73 percent ammonium and urea, along with 27 percent nitrate nitrogen. This type of fertilizer has its place, but if you have water like Kube Pak, it won’t be long before your pH comes crashing down on your crops.
Fertilizers like 15-5-15 and 13-2-13 have a lot more nitrate nitrogen, which will cause more compact growth. These types of fertilizers are basic and will at least maintain or increase the pH of your mix, while acidic fertilizers such as 20-10-20 or 21-5-20 will have a tendency to lower pH over time.
Research has shown extra phosphorus will only do one thing: cause plants to stretch. You need to understand what the alkalinity of your water is before you start choosing what type of fertilizer to apply to your crop. The rule of thumb is the higher the alkalinity in your water, the more acidic type of fertilizer you need to use in order to balance the pH in your soil.
Finally, it doesn’t matter what type of feed you use if you allow the EC of your soil to get too high. In other words, if you feed your crop 300 ppm 20-20-20 every watering and don’t check your media EC and pH, you’re heading down a dark alley. Excessive fertilizer of any type will cause the pH of your soil to sink and, thus, we have problems again.
What temperatures are you running in the greenhouse? Remember our example with vinca. This annual requires a lot of heat at the soil–not in the air. What temperature are you running at night? It’s astounding how many growers admit to me they are running their air temperature at 66 to 68°F, yet they want to know why their vinca is not growing.
Temperature can play a key part in the success of any crop, especially warm-loving crops. One of the best investments to monitor temperature in the greenhouse is an infrared thermometer. This allows you to go and “shoot” at soil temperatures and actually see what your plants feel.
Vinca requires a minimum 72°F soil temperature, so if your heat is coming from forced hot air, you will be surprised what air temperature you need to achieve to get the proper soil temperature. Crops like vinca and lisianthus will benefit from a warm start but could be seriously damaged if temperatures are not sufficient during the first few weeks after transplant.
When you look at soil, water, fertilizer and temperature in relation to plant development, they all need to work in harmony to avoid undesirable outcomes. If you don’t have a quality soil with which to start a crop, you are behind the day you begin setting pots on the bench. If you don’t know what’s in your water, then you will start to see your pH drift. Choosing the right fertilizer will keep you on the right path to nutritional perfection. The right temperature is the final piece to the puzzle of avoiding crop failures. Too low of a temperature will cause poor growth and crop issues. A good temperature is a great way to get started but overfeeding will cause your pH to crash, thus giving growers headaches.
Go back to basics. If you look at these four components before you begin a crop, you will be ensured of repeatable success.