By Nisha Joglekar, Communications Intern
Arriving over a year back from the tropical climes of India, I was struck by how green Seattle was. Beautiful flowers and trees lined every street and house in the city. I wanted my little patio to be green, too! So when the sun shone bright one March morning, I was eager to start planting.
As a newbie gardener growing vegetables in containers, I made many errors but learned a lot along the way. Below are some of the mistakes I made and how you can avoid them — with tips from experts at The Garden Hotline, a program managed by Tilth Alliance and funded by Seattle Public Utilities and King County.
1. Choosing “popular” plants rather than the right plants for your weather, season and location
Starting out, I chose “popular” veggies like tomatoes and peppers without checking to find out what’s best for our region. “A few things that people can look at before deciding on which plants to grow in a particular location, are: hours and time of sun exposure per day, wind exposure, and proximity to any impervious surfaces like brick or concrete that may generate heat and relative shade from trees or bushes,” explained Katie Vincent, a Garden Hotline educator at Tilth Alliance. She also suggests seeking out varieties that are cold tolerant or bred for disease resistance as we get a lot of fungal diseases in our area.
Check these resources compiled by the Garden Hotline to help anticipate rainfall, frost dates and more for your gardening area.
2. Not selecting the right containers
It’s important to plant in the right containers! I realized this when some of my plants started getting root bound in small pots. The experts at the Garden Hotline shared some tips with me about choosing the right pots. The size of the container depends on how much space the roots need and how deep they will grow, which depends on the plant. Large, deep containers imitate an outdoor soil profile, giving space for roots and making watering easier. In small spaces, dwarf, bush and compact varieties of tomatoes, peppers, leafy greens, radishes and most herbs are good for growing in containers. Katie Vincent at the Garden Hotline recommends choosing containers made of non-toxic materials like terra cotta, glazed pots or food grade plastic.
3. Not preparing the right soil mix
The variety of soil mixes can be confusing for a new gardener. Choosing a good quality soil that drains well and has organic matter, and watering it before I put plants in, were lessons well learned after transplanting a plant into a cheap, dry potting soil only to find the soil floating in the water. The roots of the plant eventually dried up and died.
After experimenting with different growing mediums for a year, I have settled on two for this growing season: sterile seed starting mix for germination and good quality potting soil for my transplants. Katie from the Garden Hotline recommends not using garden soil or soil from around the neighborhood in my containers as it tends to compact and not drain as well as in the garden and can potentially bring in disease.
Another aspect to preparing the soil in containers is fertilizing it. I learned that potting mix in new containers is low in minerals and nutrients and needs to be fertilized. According to the Garden Hotline, “it is recommended to use organic slow-release fertilizers. Most plants require fertilizing only once in a while. Fertilize tomato plants once when they start growing stems and leaves and then again when they start blooming and setting fruit.”
4. Overwatering or underwatering
In the beginning, I tended to overwater my plants. When I couldn’t water for a few days, I overcompensated by soaking the plant. As I started getting pest and mold problems, I realized with a little research that the soil needed to be moist, but not overtly wet. One way to check if watering is required, is to stick your finger about 2 inches into the soil and if it feels dry, then water the soil, not the leaves. Dry soil also looks light brown and the container will feel lighter than usual. Keeping a consistent watering schedule and watering in the early morning helps reduce evaporation and the damp, dark soil absorbs more heat. When it comes to my seed starts or indoor plants, I place the pots in a dish or tub of water and allow it to be slowly absorbed from the bottom.
5. Forgetting to harden off the plant and transplanting too quickly
I made the mistake of moving seedlings outside under the bright sun only to see them wilted and shriveled up at the end of the day. Plants need to acclimate slowly to outdoor weather and direct UV sunlight, says the Garden Hotline. Taking seedlings outside for a half hour on a cloudy day and then slowly increasing the length of time over a week will help them get used to the elements. This is called “hardening off” and will prevent young plants from burning under the harsh sun or from cold damage. Plants can also be hardened off outside under a cloche or a cold frame. It is also best to not transplant seedlings in the middle of a hot day to prevent transplant shock.
Hopefully these tips will help you avoid making the same mistakes I did! Patio gardening has turned out to be a fun learning experience. and the taste of fresh homegrown herbs and fruit has been incomparable to store-bought ones.
If you would like to give gardening a try and would like to learn what you can grow in your space, call the Garden Hotline with your gardening questions or try one of Tilth Alliance’s classes. You can also refer to the Maritime Northwest Garden Guide for planning your garden and maintaining it on a month-by-month basis.