How to unify legend in plot command?

I have the following code making a line plots for 2 different groups. In the legend it dosent show legend per group (only the first group is correct). I wonder if there is some command can be added to each plot group to fix the problem? BTW i am using matlab2018b.

ax = gca; 
ax.TickLength = [0.02 0.06];
set(gca,'XAxisLocation','top','YAxisLocation','left','ydir','reverse','XScale','log');
ax.XRuler.TickLabelGapOffset =-10;
ax.YLim = [0 20];
ax.XLim = [0 1];
ax.YDir= 'reverse';
x = [1 3 5 7];                  
y = [2 4 6 8];                   
z = [0.1 0.21 0.78 0.48];                      
plot([z;z], [x; y], 'LineWidth',3,'color',[0.9 0.4 0.5])
hold(gca,'on')
x = [2 8 9 14];                  
y = [3 9 14 20];                   
z = [0.9 0.1 0.71 0.38];                      
plot([z;z], [x; y], 'LineWidth',3,'color',[0.9 0.8 0.10])
hold(gca,'on')
legend("Group1_Red","Group2_Yellow")
hold(gca,'off')

Answer 1

[VBBV]

ax = gca; 
ax.TickLength = [0.02 0.06];
set(gca,'XAxisLocation','top','YAxisLocation','left','ydir','reverse','XScale','log');
ax.XRuler.TickLabelGapOffset =-10;
ax.YLim = [0 20];
ax.XLim = [0 1];
ax.YDir= 'reverse';
x = [1 3 5 7];                  
y = [2 4 6 8];                   
z = [0.1 0.21 0.78 0.48];                      
h1 = plot([z;z], [x; y], 'LineWidth',3,'color',[0.9 0.4 0.5])
hold(gca,'on')
x = [2 8 9 14];                  
y = [3 9 14 20];                   
z = [0.9 0.1 0.71 0.38];                      
h2  = plot([z;z], [x; y], 'LineWidth',3,'color',[0.9 0.8 0.10])
hold(gca,'on')
legend([h1(1) h2(1)],{"Group1_Red","Group2_Yellow"})
hold(gca,'off')

Use handles in legend

[Harr]

Dear VBBV,

Thanks for your answer! The trick about naming each plot group to h1,h2...is very useful and solved my problem :)

Best regards

/HARR