the start of summer gardening

We have very limited space in our garden (2'x5') so in order to make room for summer plantings we have to rip out our spring harvest. I have been struggling to know when I should do this as I hate to waste any of our beautiful lettuces but yesterday our spinach gave me the sign its time to go - its bolting. Bolting is when the plant is in the last stages of its life and it goes to seed - essentially its trying to reproduce before it dies. With spinach the leaves start to grow rapidly and become pointed at the ends. The plant also produces a flowering stem which will cause all energy and resources to be diverted from the root system resulting in poor harvesting and eventual death. 

Our lettuces are also starting to show signs of bolting although its not as easy to tell with them. One source stated that lettuces will produce a milky sap when on their way out. I have started to taste some bitterness but nothing extreme. Either way I will probably be digging them out this weekend and giving gifts of lettuce heads to my neighbors. 

The caterpillars have finally slowed down on eating the kale and three out of the four plants are doing well. The fourth is still growing but its color isn't as vibrant and its a bit soft to the touch. My tentative plan is to keep the three thriving kale plants but to not start eating them again till fall when the heat has broken. 

I am torn on what to do with my three strawberry plants. I have had them for two seasons so I am sort of attached but they just don't produce very well (maybe 10 strawberries per plant). I am starting to think the soil content might not be right or maybe its the amount of sunlight they are getting. I will probably end up composting them as well although it will be rather reluctantly. 

I haven't totally figured out what I will replace everything with but I know I want tomatoes and basil. Beyond that I have been thinking about cucumbers and maybe some other herbs. My plan is to get some advice at the farmer's market and go from there. More updates with summer planting to come! Have a good weekend!