Garden planting and transplanting is now in full swing and everything we want to grow can be planted out including favorites like tomato & pepper plants, squashes, potatoes, onion sets, broccoli, herbs, or greens.  But one question remains, which plants make good garden companions with each other, and which do not?   Plants affect their neighbors and the soil around them so we should try to place compatible or non-competitive plants near each other when possible. 

A similar principle applies when deciding which plant follows recently removed ones (called plant “succession”).  We don’t want to re-plant the same plant or one that needs the same soil nutrients in the same place over and over; that would risk depleting the soil and depriving the subsequent plants of nutrients that they need to be healthy.

Our second topic is succession planting – a great way to get more out of limited garden space and have your garden favorites available all season long.  Finally, we’ll cover a couple pest alerts and some thoughts about that lawn.

Here is a list of some common garden plants and recommended companions.  This doesn’t mean they are required neighbors, but we do know they are compatible, and they might even benefit from each other by repelling pests or sharing nutrients.

                                    Companions                                                 Incompatible

Green Beans:           anything (beans add Nitrogen to the soil)          Onions

Broccoli*:                   Beets, Onions, Spinach                                       Tomato, Dill

Brussels sprouts*:      Beets, Onions, Spinach                                         Tomato, Dill

Cabbage*:                 Beets, Onions, Spinach                                         Tomato, Dill

Cauliflower*:             Beets, Onions, Spinach                                         Tomato, Dill

Carrots:                      Peas, Lettuce, Tomato                                            Dill

Corn:                          Beans, Peas, Squash, Cucumbers                      Tomato

Cucumber:                Beans, Peas, Corn, Sunflowers                            Potato

Eggplant:                   Beans, Marigold                                                       ~ none ~

Lettuce:                      Carrots, Radish, Strawberry                                   ~ none ~

Onion:                        Beets, Carrots, Lettuce, Cabbage* family           Beans, Peas

Peas:                          Carrots, Radish, Cucumber, Corn, Beans           Onions

Potatoes:                   Beans, Corn, Cabbage* family, Marigolds          Tomato, Squash

Squashes:                 Corn, Beans, Nasturtium, Marigold                       Potatoes

Tomato:                      Onion, Carrot, Nasturtium, Marigold                     Potatoes, Cabbages

You can also see from this list that the classic “Three Sisters” combination (pole beans, corn & winter squash) is made of 3 mutually beneficial plants that help each other with nutrients (beans add Nitrogen), weed suppression (squash leaves smother weeds), and support (corn stalks support the climbing beans).  It is an ingenious design that works!  There are more good details online here.

Succession planting simply refers to repeat planting of a same crop over time to produce repeated harvests over time.  We have a very limited growing season, but you can still get multiple harvests of certain fast growing plants if you time them right.  Successions are great way to maximize the productivity of limited garden space too.  For example, if you plant leaf lettuce or mesclun seeds every week you should harvest fresh greens every week all summer and into the fall.  I’ve found that a short row (4-6 ft. long) of different salad greens every week produces a good supply for fresh salads into November. 

Late crops of carrots, turnips and beets can also follow (in the same place) the harvests of early salad greens.  After the garlic is harvested in late July there is time to plant fall broccoli and cauliflower plants started from seeds before 4^th of July in the same place.

Bush beans planted every 2 weeks provide a good extension of harvests too. Too much zucchini is a common problem, but if you plant one hill of 3-4 plants now and another hill in early July that will spread the harvest out so it can be enjoyed over time. The same works for herbs such as dill and cilantro that tend to mature early before we can use them in pickles and salsas. There’s some very good information and specific planting recommendation online here. 

Pest Alerts.  So far the dry weather has limited outbreaks of slugs & snails and most plant diseases but every rain shower brings them out.  Preventative applications of an iron phosphate product (Sluggo, etc.) with avoid surprise damage from slugs or snails. 

New tender growth on any plants will attract sap sucking aphids that can quickly get out of control.  Baby aphids are born pregnant!  Aphids are nearly invisible but can be found by looking for unusual ant activity on young leaves.  The ants are tending aphids for the sweet honeydew they produce (aphid pee) and are a signal that aphids are present.  Natural controls of aphids include lady beetles and wasps that we should always protect.  Beneficial wasps (98% of wasps are non-stinging) are attracted by small blossom flowers (yarrow, Queen Anne’s lace, fennel, asters, mints, etc.) which they use for nectar.  Small numbers of aphids can be finger squished and bigger infestations sprayed with insecticidal soap or neem oil, if you prefer.

Lawn thoughts.  If your higher mowing is working, you might notice more white clover blossoms appearing.  Good for bees, good for the soil (clover adds Nitrogen), and good for you!  Avoid mowing the clover blossoms once or twice and there will be free seeds that spread your clover even more.  Clover seeds also can be purchased and the benefits are significant.

What are your favorite companions or combinations to grow?  Please share your comments or questions in the space below.