Cucumber Seedlings

Cucumber Seedlings

Thursday, July 14, 2011

Cucurbit your enthusiasm

A vegetable garden is an amazing place for children to be in.  There are so many different things to learn and talk about.  I work in a collective garden as a children's coordinator with kids aged 2 to 8, and it's always interesting to see how they engage in the space.  I like to give informal gardening lessons to some of the older kids.  The cucurbit family (which includes cucumbers, melons, squash, and summer squash, like zucchini) is one of my favorite groups of plants to talk about.


These two cucumber flowers are male.  Note their very slender stems.
Cucumbers and their relatives have two different types of flowers, male, and female, which makes for an interesting conversation about pollination (They "boy" flower has to kiss the "girl" flower, and the bees help them...).  The first task is being able to tell the difference between male and female flowers.  Male flowers always have a very slender stem.  Female flowers have a thicker stem immediately below the base of the flower which resembles a miniature fruit.  The male flowers always come out first and in more numbers than the fruit-bearing female flowers.  The ratio of male to female flowers can also change on any given plant too.  Usually if the plant suffers from water or nutrient stress it will put out mostly male flowers and few females.  Bees play a critical role in all cucurbit fruit production.  Unlike tomato flowers, which can be pollinated by the wind, cucurbit flowers must be
This cucumber flower is female; the stem looks like a mini cuke
visited by bees between 15-20 times for successful fruit set. As the female flowers are often open for only a few hours on one day, timing is critical and it is very helpful to have a surplus of male pollen donors around.  If the female flower is not adequately pollinated, the fruit will not set and you will see the stem turn yellow and drop off.  If you're having problems with a lack of pollination, consider introducing bees to your garden or entice them by planting flowers.  Bramble plants (raspberries, roses, and blackberries, etc) are an excellent bee attractor with their abundant pollen and sweet smells.

When the fruit does come, having too much ripening on the vine temporarily slows female flower output.  Picking the fruit regularly (especially on cucumbers and summer squash) will encourage more fruit development.


Looking for cucumber beetles is another excellent activity.  These yellow and black striped beetles like to eat the flowers, fruits, and roots, of all cucurbit family members, and may even spread bacterial wilt disease.  They are often found on the flowers of cucurbits, which
http://en.wikipedia.org/wiki/File:Cucumber_beetle.jpg
provide an ideal mating "pad."  When the beetles are found, pick them off the flower (they don't bite) and squish them immediately!  It is important to check both open and closed flowers for the beetles as they may crawl inside and are not always immediately visible.  After a couple minutes and several beetles, the kids in my garden have become expert beetle spotters and squishers, and are eager to find the next one.

Sunday, July 10, 2011

Greens go swimming and green onion upgrades

It's pretty amazing to come back from a two-week vacation and see how much everything has grown!!  A huge thanks for my friends who stopped by to water and sample radishes.  You did excellent work!  But of course there is always much to do in the garden, so as soon as my suitcase was in the door I was out in the front doing some surveying.  The tomatoes had to be tied up, the weeds needed a lesson in humility, one giant sunflower seemed to have given up on life, and of course, harvest!

Harvesting is the best work, reaping the bounty of the labour.  I gathered a huge bag full of greens, most of which had bolted in my absence, so I had no choice but to pull the whole plant out.  Lettuce, arugula, pak choi, radishes - most of each crop came out (I need to seed more!).  My mustard greens had grown very big, but no signs of bolting so I just picked a few outer leaves from each plant to add some spiciness to the salad.  I had a nice harvest of snow peas which we tossed into stir fry that evening.  The swiss chard has made a fantastic recovery from the leaf miners (no neem oil was applied, but I did check daily for eggs and maggots before I left), and a few leaves can be harvested.  My 'multiplier green onions' seemed to be living up to their name and had not only grown to almost two feet tall, but the bulbs were expanding away from each other at the surface of the earth.  I cut off the greens just above the surface, then dug up and separated the bulbs and replanted them.  I'm not sure if that's what I'm supposed to do, but we'll see if that experiment works.  I had so many green onion trimmings I offered them to some neighbors in my building and across the street.  One of them offered me a beer in exchange for the fresh shoots.  Not a bad upgrade!

Greens go swimming
When harvesting greens, it's best to do it early in the morning before it gets too hot.  This way the plants haven't started to transpire too much and won't wilt as fast.  Later in the morning and throughout the day the leaves pump are pumping water (transpiring) through them from the roots and out through their pores (stomata).  When the leaves are picked they continue to transpire but their water source has been severed so they become dehydrated and wilt.  However, if you're like me, you won't be one of the first creatures moving about in the garden in the day and you'll find yourself harvesting in the heat.  Not to worry.  Simply bring a bucket of water with you into the garden and dunk the leaves in immediately after picking them.  This will both supply them with water and cool them off so they reduce their transpiration.  Ice water would be great but cool tap water works well too. Or you could just pick your produce and carry it into the kitchen when your done and soak them in the sink.  That works too.  However, it's best not to wait too long from the time of harvest till the leaves go swimming - you don't want the shriveling to go too far!